Agree totally with Mitchell regarding codes. Must be erased with scanner. Disconnecting of battery is no good. Mines a 96 US spec gated GTS.
Quick update: We delivered the car to Vince Hill on Monday. He found a missing rubber grommet where the wiring harness passes through the firewall. Vibration from driving caused friction at that point, which wore a bare spot in the wiring insulation. That wire then grounded to the chassis, causing one of the fuel injectors to stay open continuously, thus causing the fuel in the header. A compression test revealed all cylinders within spec, though the cylinder with the open injector was a bit lower compression than the others, but nothing that concerns him at this time, he said. So he will repair the wiring harness, replace the grommet, clean and test all fuel injectors, and do an annual service on the car. He's also going to replace the engine mounts (the old ones are collapsed) and the cat ecus (preventive maintenance as the ones in there look original).
Really good to hear this as a potential horror story like this could have been is what has prevented me from jumping into my first 355. I have been obsessing for months now and keep edging closer but so scared of the "not if but when" costs. I recently found this site which has so far been a brilliant resource in easing some of those fears so it's reassuring to hear this result.
This chafing of the wires as the wire harness goes through the firewall means the last mechanic who did the engine out was a sloppy one. The first question among Ferrari owners is "what Ferrari do you have?" and the second question is "Who is your mechanic?" The right answer for the second question is :"A very good one"
Is replacing cat ECUs a common prophylactic measure on F355s? I understand they are often the cause of frustrating operational problems, but they seem kind of expensive to replace willy-nilly. BTW, it's exciting to read the rest of the story after a BaT purchase. Not many people are fortunate enough to live near their dream car, so auto auctions are one of the only viable way to purchase them, preventing a PPI. Sent from my SM-G960U using FerrariChat.com mobile app
1) Well, if you have an unlimited budget, you could replace the ECUs willy-nilly. 2) Interchanging ECUs for faultfinding is a much cheaper option. Some cars have 3 of them. 3) Also, it's possible, for faultfinding purposes, to simulate a good ECU by using a diode and resistor or even 4) a small 1.5volt battery. 5) Technistrada offer a ready-built plug in device with inbuilt diode and resistor to do this (These can also be used on cars with no cats as a permanent solution). https://technistrada.com/355-360-456-550-575-f50-enzo/5-dummy-load-sdl-bypass.html 6) Also, Technistrada make cheaper aftermarket ECUs https://technistrada.com/355-360-456-550-575-f50-enzo/4-355-360-456-550-575-catalytic-temperature-control-station.html I use one of those for faultfinding. They also make cheap aftermarket thermocouples. 7) You could also attach monitoring equipment in series with wiring to check the TCU output. Many ways to skin a cat.
Well the new owner stated that the Tech noted that they were original. The only way he would have known that they were original is if he would have pulled them out. You see the color of the epoxy on the original ECU’s are different than the later OEM ecu’s. I asked the new owner in a previous post if the car flashed or held a Slow Down Light. She said no. With an injector stuck wide open, it’s odd it didn’t flash a SDL. I suspect the Tech felt it should have thrown the SDL or it did. He therefore would then pull the 3 ECU’s to see the epoxy on the back. So to answer your question, I have never heard of an owner having their ECU’s replaced “just because”. Something lead the Tech to pull them. Not a big job to pull them but no, not common practice to just replace them. Did he replace all 3 ? Pretty pricey parts. Julia, Congrats on the car ! I have owned one since 2003 and are amazing cars to drive. Spring isn’t too far away and you’re all set to enjoy the drives !
Personally, I am totally against replacing non critical parts that aren't broken, or haven't failed. In a case like Julia's I would have told the tech, "No, thanks", but that's me. As far as second guessing why the tech recommended replacement, when these fail, of a TC fails, the SDL and or CEL comes on. The only way the SDL stays off is if the TCU is sending out a voltage in the correct range. As for not hearing that TCU be replaced, just because, this is from a PPI I had done on a car I was considering, just because they were old: Image Unavailable, Please Login So now you have heard of it.
She (or her husband) probably did not drive it long enough for the SDL to come one. One stuck injector would do it but it has to be driven an amount of time.
Yeah 500 mile maiden voyage. The harness may have shorted to ground when they got home and in the garage. Either way, lottery winner type luck and super glad it all worked out for a new 355 owner
The epoxy surface on the main cat ECUs is exposed and no disassembly required on the ‘98 5.2 car. Not sure about the 2.7’s.
Or epoxy starting to crack. A very common problem which then allows water intrusion. Then the ECU may start exhibiting erratic behaviors.
One thing I have never understood. If the epoxy is cracking but the units are still working fine, why not just seal them with... Image Unavailable, Please Login If epoxy cracking (i.e. the seal is broken) and water intrusion is really the problem why wouldn't you try this? It's like, if an oil seal leaks you don't replace the engine.
Hi Julia and welcome and congrats I personally would leave the original cat ecu’s and just buy 1 spare. My ordinal ones are still in there for 2 of them but have had to replace 1 of the 3. I will tell you from my personal experience is that I had less problems when I drove my car all most every day vs when it sits. You will enjoy it and everything is fixable. Take care and glad you sorted the problem and thank you for sharing as some don’t.
Ah, I was wondering if that was a possibility, since some people run test pipes. Personally, dirty car exhaust makes me sick quickly, and with it being a Spider, I didn't want to remove the cats.