Hi Fellas, So my question is, does anyone know the Bosch part number for the O2 sensors on the 348. Specifically for Ferrari part number 142514. (as opposed to 121515) Here is the background to this….. Last summer car wasn’t driving well. Had idle issues, hot start issues and check engine lights all over the place. Frankly car was in need of a service. So over the winter I have installed : New temp sensors New O2 sensors MAFS out for rebuild Injectors out for service / cleaning Installed the engine side of the Gold kit. New thermostat New Cam Phase sensors New Crank sensors Since installing all of this, car has got significantly better. Hot start and idle issues all gone. Yeah ! Took her out for a spin and the stupid CEL came on. Pulled the codes, and 4121 seemed to be the issue. From research this seems to be the Exhaust ECU. I wasn’t getting any slow down lights, but the CEL’s were on and off. So, I found a thread which suggested just disconnecting the Exhaust ECU. This I did. And tada, the CEL lights were gone. Drove for 60+ miles and all perfect. Was about to declare victory, but then I considered that the Exhaust ECU’s are there for a reason, so decided to replace the CATs with straight pipes. (I live in NY state, and after 25 years they don’t do an emissions test, and for the few hundred miles I drive it I figured it didn’t matter) So, I installed the straight pipes. Took the car out for a spin, and all good until she warms up. The then CEL lights come on. Permanently. Pulled the codes and they are still 4121 (how can that be, if the Exhaust ECU is unplugged….) as well as 1212, 1121. From research I’m told that the motronics don’t go into closed loop, i.e. use the O2 sensors, until the car is at normal operating temp. The CEL lights now come on an EXACTLY the same time, and stay on, when the car has warmed up. Until the next day when the engine is cold again. So I read up on how O2 sensors work, and they seem to be heat based. I also went through the parts diagrams and noticed that on cars without cars the O2 sensor is part number 142514 and if you have CATs then it’s 121515. So I concluded that they have different O2 sensors on straight pipe cars to CAT cars. This seemed to make sense to me, as the CAT operates at a far higher temp than the straight pipe. Ugghh… So I went on the superperformance website, and they list the two O2 sensos. The 142514 one is described as a “Lambda Sensor” whereas the 121515 is described as a “Oxygen Sensor” So, I thought, great – I’ll just order the 142514 ones. Well I got them this week. They are Bosch part number 0 258 003 222. I tried installing them today, and noticed that the old ones I took off were also the same Bosch part number. Of course, I still installed them, and went out for a spin, and guess what. The CEL lights come on and stay on as soon as the car has warmed up…….Ugghhh So – I don’t know if they sent me the wrong part here, but I was wondering if anyone knew of the Bosch part number for the O2 sensor on cars without CATS ? I’m also considering just taking the bulibs out of the CEL lights.....as the car is running great…… Any help ? Thanks in advance Jason
Jason, for cat efficiency related messages, have you read about O2 sensor extenders (with steel wool in them) to fool the ECU? For cat temperature-related issues (Slow down lights, etc)... If disconnecting the temperature sensors is not fooling the ECU, you can simulate cat normal operating temperature by disconnecting the plug from the Cat (temperature) control units (TCUs) and fitting these simple plugs to the wiring harness going to ECU: https://www.ferrarichat.com/forum/threads/simple-2-7-slow-down-ecu-replacement-only-for-no-cats.538719/ I believe it works on 2.7 and 5.2 cars. Gothspeed used to provide an aftermarket TCU for no cat exhaust systems but I'm not sure if they are still available (e.g. at Ricambi).
Okay after rereading your post you may want to: 1) Put new EPROMs in both Motronic ECUs. Here is the DIY. https://www.ferrarichat.com/forum/threads/348-ecu-removal-chip-removal.351819/ 2) Repin the the T55 connectors to both Motronic ECUs. Here is how I did it inexpensively. https://www.ferrarichat.com/forum/threads/348-motronic-2-7-connector-harness-repin.444155/
Sorry, Jason.. I just realised that you were talking about the 348... I'm not sure how much of the 355 stuff is applicable to your car.
Hi, Thank you for all the replies. Here is an update for you…. I mentioned in this post part number 121515 and this is misleading. Table 14A on the ricambi website has this sensor, but it’s labeled as for Motronic 2.5. Table 14 has part number 142514 and table 14A has part number 142514, 146650 and 151667. So there are plenty of others to choose from… I spoke to the guy at superperformance today, and he told me that part 146650 is in fact bosch part number 0 258 003 240. (However if you google Ferrari 146650 I found something which implies that the bosch part # is 0258003240 – so who knows) I also spoke to Daniel at Ricambi and he told me that when he had his 348 he removed the cats, but used the same O2 sensors which put into question the whole theory that perhaps they were different. I decided to do some diagnostics myself. I removed the air box, but left the MAFs on, so that I could access the O2 sensors. My understanding of the O2 sensor is that one of the plugs is a 12V circuit to heat the sensor, and the other plug is the data circuit. My understanding also is that the O2 sensor actually generates an electrical current (I’m told between 0.1 and 0.9 V) and the 12V circuit is only there to help it get hot. Turns out this isn’t the case. So, armed with my multimeter, I pulled off the two plugs for the 1-4 bank and tested which is which. The Male connector (from the O2 sensor’s perspective, not the engine) is the one which has the 12V. the other is the data. On the 1-4 bank, I had a 12V on the one plug, and one the other plug I was getting readings sorta in the range of 0.1-0.9. I would actually say it was in the range of 0.0001 -> 0.9, not sure if that is correct, but at least it was doing something. Over to the other bank, and I wasn’t getting a 12V signal or any data. First of all I swapped the two O2 sensors, and got the same result, so it’s not the sensors. (Now, I will say, that I have purchase several things from SR, and although they are not cheap their products are very good. However when I installed the gold kit (I’ve only done the engine not the motronic plugs yet) the kit only contains the female side for the O2 sensors. This is a bit crap, because I would have thought it’s the data side that you want perfect, and not the heating plug, but there you go.) I carefully removed the 5-8 bank 12V female engine side plug from it’s bracket, and after peeling back the boot, turns out that one of the wires was not crimped correctly. So, long story short, I pulled this off, recrimped the two wires and put it all back again. This yielded data from the 5-8 O2 sensor. (Again – this is a bit weird – cause it seems that the O2 sensors only work if they have a 12V heating circuit, which is contrary to everything I’ve read about O2 sensors) Although I was happy at having found a problem, I couldn’t seem to figure out why both check engine lights were coming on, when it was only one bank which had the faulty wiring. But, given that I was out of ideas, I put it all back together, pulled the codes, reset the ECU codes, reset the ECU, let it warm up, went out for a spin, and withing 1 miles both CEL lights came back on. I even reinstalled and hooked up the Exhaust ECUs. Same result. (although not getting the 4121 code anymore) So…….bit stuck now. The codes I am getting are 1212, 1121 and 1121. All seem to be “lamda” related. Another odd thing is this. I can never reproduce the code with the car in the garage. i.e. leaving it running at idle, or even revving in the garage doesn’t seem to work. Only when I take it out on the road does it light up. Ernie – I will install the motronic plug with the gold kit. It’s on the list. I have also read your post about replacing the ECU chip. I do have a question on that. Where do you buy the new chip ? I’m off on vacation tomorrow, so no clue when I’m going to get to look at this again…. Ugghh
12V is the heater signal The true O2 signal is between 0V to 900 mV so you are in the ball park. If you are having Lamda regulation CEL then it may not always be the o2 sensors. Especially if you have already changed to new ones. The codes are saying "I read the O2 signal, I adjust the stoichiometric, and I can't seem to get the O2 signal to where I want it to be..." Maybe inside the ECU is where the fault is. so, a new chip may just do it.
Isn't it possible that you have a real lambda regulation issue that throws a light and nothing wrong with the o2 sensors? There are a bunch of things that can be wrong. In that era there were few codes to cover a lot of parts. It is only with increasing federal demand and OBD2 changing protocols that an SD can tell you its a left cooling fan or a mode $6 identification of a specific evap valve. I would stick a wide band in there and see what lambda really is at full operating temp. Results of that can lead you down a sound path of diagnosis.
I got one set of EPROMs (with the factory spider mapping) from fchatter 3forty8, and the other set (with a Stooge tune) from fchatter SoCal. I still haven't install the set I got from Tim (SoCal) yet.
Hi - thank you again for the replies. I'm not really sure what "I would stick a wide band in there and see what lambda really is" actually means. If you have any more info on that, would be very helpful. I do agree that it could be a pile of things causing this, but I've pretty much changed or serviced all the major bits (O2 sensors, temp sensors, injectors, thermostat, crank sensors, cam sensor) and it WAS WORKING when I unplugged the Exhaust ECU and had the original CATs on there. Since then all i've changed is replacing the CATs with the straight pipes and since then it's CEL all over the place. I think i'm going to buy some more Exhaust sealling rings, and take off the pipe and reinstall. Perhaps there is a leak at the junction where the pipe meets the manifold and it's letting in O2 from the outside. After that I got nothing. Ernie, I take your point on replacing the wiring at the motronic plug, and at some point I will do this, but I feel like this is not the fault because both lights come on at exactly the same time, and this always occurs when the car's warmed up. So I feel like it hits the "operating temp", the O2's kick in as the ECU goes to closed loop and then it throws errors. That's my theory. Then again, I am absolutely out of ideas, so I might as well repin the T55 connector.... Can somebody tell me what the cam crank sensor does. There is only one of these, so i'm guessing this isn't critical to the ECU ? Is this for the rev counter ? Would love to know the answer to that.... Ernie - would you like to sell one of your EPROMS ? I will PM 3forty8 and SoCal to see if they will sell me one. J
In reply to the OP's original question, I am attaching a document that will help cross-referencing Bosch/Ferrari parts for the 348 as well as many other models. Hope this helps!
EPROMs, Socal1 (the 1 is important) will send them to you for nothing, he is that generous. On the sensor, you really mean the Cam Phase Sensor (and not the conflicting Cam Crank sensor name). That is the one attached to the input cam shaft on Bank 1. It is very important to the ECU because it tells the ECU the cam position in relationship to the crank shaft so that the ECU can tell if it is TDC compression stroke or TDC exhaust stroke. As far as your problem, I would try to do a smoke test on the engine from the input to the MAF to see if there are any minor leaks.
Again - thank you for the replies. I did contract Socal1 and had a good correspondence there. Update on the stupid car.... Got some time yesterday to have another play around. Here is what I did : I mentioned above, that one of the sealing rings on the exhaust straight pipe (where it joins the exhaust manifold, upstream from the O2 sensor) looked like it had cracked when I installed it. My concern was that perhaps it was "leaking" and pulling in O2 from the outstide and throwing the O2 sensors off. So I got some more sealing rings, took the pipe out and reinstalled with the new sealing ring, making sure I didn't tightened the bolts so tight that it would crush it. I did this on both sides. Put the wheels back on, and out for a spin. Same results. after the car warms up both CEL lights came on at exactly the same time. Ugghhh... As I was now officially out of ideas, I thought maybe there was something wrong with the air injection valves. If you look at this diagram : https://www.ricambiamerica.com/car-diagrams/ferrari/v6-v8/348-group/348-1989-1992/air-injection-device-motronic-2-7.html The parts in question are items 13, 16 and 8. I don't know what these parts are called, but the ricambi website calls part 13 a "depression tank", part 16 a "solenoid" and part 8 a "cut-off valve". Not sure if those are the technical names.... The reason that I decided to investigate this area, is because I noticed that the depression tank had 3 connections to it, but only 2 were connected. I was all excited for a mo, as I thought perhaps my problem was a simple as one of the connections falling off, but it turns out after studying the parts diagram that the third one is supposed to be off...oh well. I still took it apart. Here is my guess as to what this parts do. The depression tank, I think, somehow amplifies the vacuum that the plenum is producing. Not sure if that's right, but my hint was it says "Amp" on the "output" connector. This is connected to 3 solenoid valves, 2 of which control the air injection and the other does the valve thing in the plenium. (I do understand what this valve in the plenium does - I think. It's the item 13 on table 12. I believe that under certain circumstances the ECU opens this valve to allow the 2 halves of the plenum to "share the air", or something like that. I do have a question however. If the ECU throws a code 1212, which means the "Lambda regulation multiplicative valve for self adaptation", is this code referring to this valve in table 12, item 13 ?) Anyway, here is what I did, and the results I got. The results are weird..... Note : and this fact, I think, is important, that I only did this on the 5-8 bank. Firstly I disconnected the pleumim tube to the depression tank, and verified with the engine running that this tube "sucks". Then I reinstalled the tube onto the depression tank. The output tube of the depression tank is connected to a 2 way connector, so I disconnected that, and connected the tube directly onto the "cut-off-valve" and verified (by trying or not to blow air throw it) that it indeed cut's off. This seems to work, so I verified that the cut off valve was working. Then I took the solenoid off, wired up two wires to the battery, and confirmed that when it gets power I hear a clicking. I also verified that the clicking opened and close the solenoid by trying to blow air through it. I also hooked up the tubes again, and verified that when I put a electrical connection across the solenoid, that it does in fact open the cut off valve. (i.e. there is no hole in the vacuum tubes which could be failing). All of this seemed to be working correctly. as I said, I only did this on the 5-8 bank. I didn't test the 1-4 bank solenoid valve or cut-off valve. I also didn't test the valve underneath the plenum as I couldn't get to it. So here's the werid thing. And this could be just nothing, or it could be something. I then went out for a drive. after approx. 10-15miles (i.e. engine warmed up) the 1-4 CEL light came on. HOWEVER THE 5-8 CEL DIDN'T. In the past these two lights came on at exactly the same time. For a little while, I was all happy that perhaps my testing of the air injection system on 5-8 bank had somehow fixed this...... Unfortunately not however, as after approx. another 15 miles the 1-4 bank also came on..... I have no idea if these results mean anything. Was it just luck that this time the 1-4 CEL didn't come on at the same time as the 5-8 CEL ? Or perhaps my manual testing of it somehow "tricked it" into working, albeit for a short time ? Hmmm..... Thoughts ?
I thought the 348 CEL's come on under 1 of 3 scenarios depending on heat measured in the cat. That's the whole point of getting you to slow down, in theory, the cats cool down and the lights go out. Excessive cat heat is caused generally by unburned fuel that gets cooked in the cat and, consequently, heats it up. Supposedly, excessive leaning might cause this as well, but I am not sure that is what happens in the cat to be measured by the O2 sensor. These 348's are not that "smart" in this capacity. Are we chasing down a heat issue, fuel mixture or something else? Finding the cause will help find the failing part(s). Given that both sides show CEL's, obviously it's a problem common to both sides of the engine. Remember that they operate independently, for the most part. It is rare to see both sides manifest CEL's. I know I get them when my car riches out too much. I can actually make it happen if I try with inconsistent driving.
Random thoughts: Vince's post immediately above describes the function of the SDLs more than the CELs. The air injection system becomes redundant when you remove the converters. In fact, one of the big pluses of not having converters is the opportunity to remove (and store for future owners) the entire air injection system. Unobtanium Supply offers plugs for the individual ports in the heads but I'm not sure how easy it is to access the air injection manifold fittings with the engine in the car. However, you can either remove the rubber hoses from the one way valves on the air injection manifolds and cap them using silicon caps or you can remove the one way valves altogether and use plumbing caps to close off the air injection manifolds if you don't want to try to mess with removing the injection manifolds themselves. You can also remove the vacuum system that actuates the air injection, including the fitting from the left plenum, which can then be plugged using either a 5 or 6 mm screw. That eliminates a few vacuum hoses, two solenoids, a vacuum reservoir, etc, which means far fewer opportunities for leaks... in addition to a cleaner engine bay. Considering all the excellent work you've done so far, tracing and removing the air injection system should be both easy and fruitful in terms of simplifying the underhood plumbing. Past that I completely concur with FBB's suggestion of monitoring your air/fuel ratios to see what's *really* going on. Removing the restrictive converters really allows the engine to breathe, so you want to know what your AFMs are doing, especially since you've changed a number of components and presumably have not yet dialed in the rebuilt MAFs. While it was nowhere near as bad, my car was throwing random SDLs even after upgrading the TCs to Dr Bob's units, and the occasional CEL cropped up as well. Since I'm focused on tuning for performance (using only fully reversible mods) the converters were the first things to go, along with the installation of two new Bosch O2 sensors (0 258 003 222-- the 348 sensors are in front of the catalysts, and therefore unaffected by them, so use the specified part number). I'm a ways behind you because the exhaust was just refitted and some of the fasteners are not yet tightened. So no help from an experience perspective, although I do have many years experience working on similar systems. I fully expect my AFMs to be way out of spec, so once I'm driving the car again using a WBO2 setup to monitor AFMs in real time will be very near the top of the to-do list. In your case it'd help point you in the right direction, as well as ensuring that your flamefront hasn't become a cutting torch. Best of luck and please keep us up to date with what you find. Your posts are great fodder for the archives.
Apparently can't edit my post above so need to correct a couple of things-- after studying the diagram it seems that the vacuum reservoir* (stores emptiness), AKA the "depression tank" (stores sadness) does indeed share purpose with the manifold butterfly, so both it and the vacuum connection at the rear of the left plenum need to be retained. However, you can still eliminate the two solenoid valves that actuate the air injection by connecting the plenum butterfly solenoid directly to one port on the "depression tank" and connecting the other "depression tank" port to the vacuum source at the rear of the left plenum. *Not 100% certain of its purpose here, but in the past I've had to add what we jokingly referred to as a vacuum capacitor to high performance engines to dampen the pulsations in the intake tract. Wouldn't surprise me at all if the true purpose of the "container of sadness" is just to smooth out the vacuum source so that the valves at the end of the line don't chatter at idle.
Hi, Mike – I did follow most of your post. I don’t fully understand why I could remove the Air Injection system. I did do this, with the verrell plugs, on my 308. However I would have thought (???) that if the O2 sensor detected a rich mixture, the ECU would open the air injection system – no ? i.e. the air injection system is one of the tools the ECU has to keep the mixture “correct”, and without that I would have thought it would get confused ? That’s a total guess btw, but makes logical sense to me…… About the middle of your post, is where I start to lose it. I’m not sure what AFM, SDL and WBO2 means. I’m guessing that AFM means Air/Fuel mixture, but no clue on the others. I’m also very interested in the “suggestion of monitoring your air/fuel ratios” and “dialed in the rebuilt MAFs”. In FBB’s post he mentions a “wide band” and I don’t know what that is either. The MAFs I have set to the correct (can’t remember off the top of my head) Ohm setting. When they came back from being rebuilt they were not set correctly. (or perhaps they were ? and this is my problem ?) The other thing I should add is that the car is in the middle of nowhere. And I mean nowhere. The nearest tire place is 50 miles away. It would be a very serious effort on my part to bring the car to a shop that actually knew what they were doing. So…..if you guys can enlighten me on “dialing in the MAFs” and “monitoring the AF ratio” without having to take it to a shop, that would be most most helpful. Is this something that you can do at home ? In the meantime, I have decided to build something to try and diagnose this myself. The technical name for what I’m trying to build (I recently discovered) is a breakout board. The idea is to detach one of the ECUs and have some kind of electrical harness that I can plug into the engine side, and the ECU side, and then have the various electrical connections available for monitoring. My work previously on using the multi-meter to monitor the O2 sensors seemed fruitful. (or at least seems better than randomly changing out parts hoping for the best – which was my previous approach) I found a company in the UK called Simtek which sells the male and female T55 connectors, so I bought that along with some other connectors which I thought might be useful….
Image Unavailable, Please Login Here is my little package from them. These are the other connectors....
Image Unavailable, Please Login The male plug is a bit of a pig, as it doesn’t have connector pins but instead appear to go right into a board. Hmmm....
Image Unavailable, Please Login Got me some wire, the pins, crimpers from the gold kit. I used 16 gauge wire.