1996, 5.2 US model, TUBI silencer so I’m trying to fix an issue(s), and rather than throw money at more parts I’d like to get opinions first. So issues - ticking sound at idle which goes away once the engine is up to temperature - the cars going into limp mode/dropping a bank, usually this is after 10-20 minutes of driving, although sometimes I’ll start the car cold and it’s on one bank After a journey where it dropped a bank I took temperature readings from the headers and the left hand side header was roughly 30 degrees Celsius less than the other, so I “assume” this is the bank being dropped I have code read and I’m getting the following P1449 P1448 P1447 P1691 P0140 P1117 P1121 P0102 P1452 now then to get an idea on parts age, the car last had its major engine out service 4 years ago, this service was - cam belt - cam tensioner - new belts all round - 2 new coil packs - spark plugs -oil filter, fuel filter, oil etc since having this bank dropping issue, - new spark plugs - new fuel filter - new HT leads - new battery. I’m suspecting the cat ECU’s, my car has 3 ECUs, 1 on the upper left of the engine bay, and 2 more behind the rear right wheel, all of these are green gelled, the one in the engine bay displaying gaps around the edge ( need to inspect the other 2) I called Ferrari for prices and they were suprised I had 3 ECU’s, as they said it should only have 2, does anyone know why mine has 3, and what the 3rd does? They are all connected. Now the ticking issue, I performed a smoke test to look for any leaks on the headers, what I found was I had pretty bad leaks on both the clamps, to the extent I couldn’t inspect the headers due to the amount of smoke could this be causing the ticking? And could it also be causing the exhaust ecus to throw codes? I’ve attached 3 images, 2 from the smoke test and the most recent spark plugs I removed my next steps were to fix the exhaust leaks to I can inspect the headers, and I was planning on ordered 3 cat ecus, and 2 thermocouples from technistrada to rule all those out. Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login
Your codes are ranging from evaporative emissions failures to O2 sensors out of range or failed and catalyst insufficiency to a failed MAF and finally the CEL bulb having been removed. Is your CEL on right now? If it is not it's very likely the bulb has been removed and putting one back in will fix a few codes. For the evap codes I would start by making sure everything in the evap system is still installed, connected and sealed. Your smoke generator should be able to make short work of that. It appears from your photos that you have sport catalytic converters installed which will generate most of the exhaust emissions related codes you are seeing and those may be compounded by failed O2 sensors. Failed cat ECUs and/or probes are the most likely cause of the bank shut down/limp mode you are getting. As far as the exhaust leak at the clamp goes, that stamped steel compression clamp for the muffler flange is not stock and it appears the sliding one on the cat has been welded on which is not correct. The welded on clamp is most likely cracked which is causing the massive leak and yes that could be the cause of the ticking sound. You need to disassemble the clamps, cut the welded on one off of your cat, assess the condition of the connection and change the clamps back to the factory configuration to seal the leak. Considering all your codes, it appears someone has been extensively modifying the emissions equipment on your car so the first step is to figure out what has been altered or removed and put it back to the stock configuration. The sport cats will always cause catalyst related codes and adding post cat O2 sensor extenders to fool the system may stop the code generation but will also prevent your emissions system from getting to a readiness state. If your car needs to pass an emissions check, the only way that will be possible will be to replace the sport cats with stock ones. With all that being said, does the engine run correctly when it is not in limp mode? Those old spark plugs in your photo look very carbon fouled indicating a very rich fuel to air mixture.
I was under the impression my car only had a tubi silencer fitted, and that the rest of the system was stock, so you think I have sports cats? I can take more photos if required, yes a previous owner had removed the dash bulbs, I have put these back in and the check engine light, and slow down light are illuminated. Thanks for the suggestions regarding the exhaust clamp leak. Before these issues the car seems to run ok, it did always smell a little rich to me but I was told they all do, the exhaust would pop frequently but again, I was told the tubi would create that? I will order the exhaust ECU’s and probes from technistrada, in the meantime I will have the leak fixed
Regarding the old spark plugs, the old leads were quite wet in and poor condition, new leads have been fitted with the new spark plugs, could that have had the effect you describe? or the MAF by any chance?
Yes, please take more photos of the cats. The typical sport cats have a distinctive shape to them so it is easy to spot them. The original cats were prone to core failure so it is very common to replace them with aftermarket units. Misfiring spark plugs could cause the carbon fouling but they also cause misfire codes and I did not see any of those in your list. It is quite possible your MAF has failed and is causing a rich mixture which in turn could be causing the cats to overheat and cause the limp mode. Before you start looking further into the MAF though, clear the codes and take it for another drive to see which codes set again now that you have the CEL light bulb installed again.
Also that exhaust ticking could be a crack in one of your headers if you still have the originals installed. They originals are very prone to cracks and leaks.
Do these help Also I just looked and missed these codes P1454 P1445 (pending) P1446 (pending) Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login
Those other codes you found are referencing more evaporative system faults. There has to be a very large leak that is venting the fuel tank to the atmosphere. It shouldn't affect the running of the engine but those codes will keep resetting until the leak or failed valves can be repaired. The P1445 is most likely related to the slow down and limp mode problems you are having. That sure looks like an aftermarket cat from your photos and probably has a free flowing core in it so it will not be able to sufficiently catalyze the exhaust gases. This will throw catalyst insufficiency codes and the post O2 sensor will be sending the signal for those codes. It looks like someone tried to seal the cat to muffler interface at the clamps with some kind of exhaust sealer so this isn't the first time there has been exhaust leaks there. My suggestion for where to start would be to repair the exhaust clamp leaks and figure out what has gone very wrong with the evap system and fix that. Then get some extenders for your post cat O2 sensors and install the cat ECUs and themocouples you just purchased. Clear all the codes again and take the car for a drive to see if you get any repeat or new codes. It is probably going to take some time to get to the bottom of everything so be patient.
Your exhaust leaks are massive. Get the exhaust buttoned up before doing anything else. There is really no point trying to diagnose any other problems when the exhaust system has holes in it.
Who is "Ferrari"? 3 ECUs are normal. One is for sensing the exhaust temperature just after the cat bypass valve. It senses whether your valve is open or closed.
Placed the order for the ecus and probes, whilst I’m Waiting for those I’ll tend to the exhaust and have a look at the evap system. I don’t particularly want to change the sports cats for stock, if I’m reading it correctly the only issue this is causing with the o2 sensors is emissions related. and my local Ferrari dealership is who I called, they were adamant there were only 2.
Usually a sign that one of your thermocouple ECUs is faulty. They're probably relying on their parts diagrams/computers rather than experience.
1. Don't call that Ferrari dealer again. If they can't count to 3, they are not worth their spit. They also don't have any experience fixing 29 years old Ferrari. 2. You are competing with @ketel for the most number of CEL on a 96-355. (He had 13) 3. By the way, Tubi muffler do not "pop" From the look of your pictures, your engine is in ... sad shape. It will take some work to get sorted out. Your car had all the "normal" problems with a 5.2 Ferrari: a) Thermal control units b) Exhaust leaks c) Non stock cat converters d) Engine running poorly Here is what I would do if I were you (and I had a 96 355 for 10 years). Replace all three TCUs (since you have them on order) Remove the cats, inspect the inside for melted cat material, replace the clamps with proper clamps. Replace all four O2 sensors. They are not too expensive anymore. Smoke test the evaporative emission system. Pay special attention to the front left corner of the engine bay. Item 27 (all three right angle ones) are likely to be cracked needing replacement. Image Unavailable, Please Login Replace all eight spark plugs, replace the ignition wires. Clear the CEL codes with an OBD2 scanner. Disconnect the batter for 5 minutes. Reconnect the battery and let the car idle for 10 minutes without touching anything. Get in, drive it and see what error codes are fixed and what else is coming up. Then, work on those remaining ones.
Ok so I’ve improved the exhaust leak, it’s 95% better now, I plan to fix this completely in the next couple of months as I plan to replace the starter motor and clutch so it will be much easier with the bumper removed etc, for now I just want to solve the limp mode issue so I know the cars ok before I start stripping the back end off. so yes, I’ve cleared the codes and taken the car for a run, first of all the slow down light was flashing as soon as the car started, after about 20 minutes the car dropped a bank and the slow down light changed to constant. I then restarted the car and got another 10 minutes before the same occurred. so im hoping the cat ecus from technistrada which are currently on a flight over to the UK, will fix this issue. the codes when i got home were: 1449 1448 1447 1691 1452 1117 0140 1454 1121
Using 360 code descriptions (so there may be some discrepancies) 1449 Cat temp bank 2. Range/performance (min/max): Check wiring, check Thermocouple ECU 1448 Cat bypass flap circuit malfunction (range/performance min/max): Check wiring, check valve, check vacuum leakage 1447 not listed (may be exclusively 355) 1691 not listed (may be exclusively 455) 1452 Secondary Air Pump circuit (open (signal)): Not present 1117 O2 Sensor heater circuit (Downstream of cat) Bank 1 (Short to ground): Check wiring, check O2 sensor impedence, continuity and value, 0140 O2 Sensor circuit (downstream) Bank 1 (No activity detected). Check wiring, check signal (0.97~1.05), check injectors and wiring, check ignition coil and wiring, check emissions. 1454 Catalyst protection active (bank 2) (max). Check injector wiring, check ignition coil wiring, check all injector functionality, check emisions. 1121 O2 sensor heater circuit (downstream of cat) (Bank 2) (Short to ground): Check wiring, check O2 sensor impedence, continuity and value,.. Take all these descriptions with a grain of salt. The 360 O2 sensor heater circuits are quite different from the 355's. On the 355, heater power comes from a single source. You would think any short to ground would affect all O2 heaters. Feedback to the ECU about heater status is also done in sensor pairs (precat sensors is one pair, postcat sensors is another pair). Regarding "1452 Secondary Air Pump circuit (open (signal)): Not present": Not sure what this means on the F355. The ECU controls a single relay which provides power to both the pump and the solenoid valve (for controlling the secondary air valve). Is the message saying the wiring or relay coil is open circuit? The ECU does monitor the O2 values during pump operation, so that is providing feedback about the secondary air system. I'm assuming you've made no typographical errors with your codes. Also, I'm assuming the plugs on your exhaust bypass and right hand (bank 1) cat thermocouples haven't been swapped around So I'm assuming the problems didn't start right after the major?
No these issues have only recently started, despite the amount of codes, and the look of those clamps the car ran quite well prior to this. I missed a post from the other day (apologies), the popping from the exhaust only happens occasionally when I come off the throttle, and I have recently installed new plug wires and plugs. I haven’t messed with any of the cat ecus, so unless they were swapped during its major a few years ago, but then again I’d have throught issues would have occurred nearer the time if that was the case, I’ve driven around 15,000 miles since then. is bank 2 the left hand side of the engine if looking from Behind the car? If so the cat ecu on that side has a clear crack
I am willing to bet that your thermal control units are bad and once you get the new ones in, half of the codes will go away. The o2 heater and inactivity codes are likely fuses. There is at least one fuse controlling the power to the sensors. Get those out of the way, then you will get down to manageable number of codes.
I had almost that exact same list 14 years ago. Here are my old notes form forever ago: P1145 = Pass side CAT ECU P1449 = Drivers side CAT ECU P1448 = By Pass Valve P1447 or 1446 = CEL burnt out or not installed P1691 = Not sure P0159 = O2 sensor slow response Bank 2 sensor 2 P0160 = O2 sensor no activity Bank 2 sensor 2 P0432 = Cat inefficiency code Bank2 P0422 = Cat inefficiency code Bank 1 P1121 = Crank sensor (might be your engine bank shut down reason?) Four codes for O2 sensors P1117 = P1118 = P1119 = O2 Bank 2 Sensor 1 P1121 = P1452 = Evap System Failure / air injection system. I replaced all three thermocouples (157501 - Ricambi looks sold out) https://awitalian.com/product/ferrari-exhaust-thermocouple-tstcplv8.html/ I replaced all four O2 sensors: Pre -Cat = Bosch 13819 - https://www.amazon.com/dp/B001D0CG9O?ref_=ppx_hzsearch_conn_dt_b_fed_asin_title_1 Post-Cat = Bosch 13820 - https://www.amazon.com/dp/B001D0CG9Y?ref_=ppx_hzsearch_conn_dt_b_fed_asin_title_1 You can get them on Amazon as plug and play. Ebay has them cheaper if you are feeling lucky. The CAT ECU's are in back with L/H side having one and the R/H side with two. The R/H side has one ECU for the CAT and the other for the bypass valve. If the leads into them are reversed, the car will react with slow down lights and possibly shutting a bank down. I had a similar issue 14 years ago with the slow down light always coming on. I swapped the connections and this issue was corrected. Lastly, check the electrical connection blocks behind the passenger seat by the engine ECU. Especially the white one with like 16 pins. Once the engine out is complete, snapping that block back together I had a pin back out of the block giving me fits on a code. Make sure everything is connected properly.
If these codes are related to O2 heater power for the 355, check fuse 22 in the footwell Image Unavailable, Please Login Note that power only comes onto the fuse when the engine is running. It uses the fuel pump relay. Power goes from the relay panel to the 9 pin plug near the Motronics ECU behind the RH seat (I can't remember if this is a clear or white plug). It is a violet wire. It then goes on to the O2 sensors via splices. The heater wires are the white wires on the O2 sensors.
Thanks for all the suggestions, gives me something to work with. regarding the potential mixed up wires on the two Cat ecus behind the rear wheel, I assume the course of action here would be to first install the 3 new ecus I have coming, and then see if the slow down light disappears, if I try swapping them with the old ones in situ I’ll perhaps be non the wiser because my 5.2 only has the one slow down light, so if the bank 2 ecu is toast then the light will still light up regardless of what I do with the other 2?, happy to be corrected however. whilst on the ECU’s, the single ecu on bank 2 has the tell tale signs of cracks, I couldn’t see any cracks on the other 2 although I was quite difficult to inspect them properly whilst on the car. Also I couldn’t see any leaks on the headers during the smoke test which is good. I’ll check that fuse out later today
@Qavion Ian, are the wiring colors different for the ECU that measures the bypass valve versus the ECU that measures the Cat? I seem to recall tracking that down and correcting the connections....more on accuracy than a guess. Maybe I can find my wiring diagrams later today.
