Ok, so I posted earlier about getting SDLs over the last week. I cleared the codes and started off today. After 20 miles of normal driving the 355 went into limp mode. I pulled over and turned off the engine for 10 mins so it could cool. I poked around in the engine bay and decided to try and disconnect the drivers side thermocouple connects from the ECU. I remember this working in the past. I fired up and the SDL light was flashing but the engine was not in limp mode. I drove normally for about 10 miles and then the 355 went into limp mode again. She coughed and burbled. I limped off the freeway and pulled over. I popped the rear deck lid and in the dark of the evening I could see the drivers side headers and cat were red hot. I waited a while, reconnected the thermocouple connects to its ECU and drove very slowly another few miles and parked the 355 for the night. What's the wisdom here? Is there a quick explanation to this behavior and why the drivers side bank headers and car got so hot. Did it have to do with disconnecting the thermocouple connects? For the record the O2 sensors and thermocouple ECUs were all replaced in the past few months. I'm trying to still make it to LA for the Stoogefest so what can I do to correct the problem at least temporarily so I can get 500 miles in normal driving and access the collective wisdom of the stooges on this? Let me know ASAP. Thx all. ketel
Ketel. I responded to your previous thread on this subject and gave you a starting point for diagnosing your sdl issues. I also told you that unplugging the Tc will send a 5 v signal to the ecu which will throw a sdl for sure. Unplugging the Tc will not create a overheated bank. It is strictly a warning system and does not affect fuel trim. If you replaced all of your cat ecu and you do not want to tap the outputs and properly diagnose what's going on then I would blindly replace your Tc now. If it was my car I would put a positap on all three cat ecu outputs and properly determine what they are sending to the ecu that is causing it to go into limp mode. If you truly do have an overheated cat situation beyond malfunctioning warning system then that's a different topic.
The one thing that seems different here than a typical TCU/Thermocouple malfunction is that you say the left side header and cat were glowing red. So...it could be that you have a legitimate cat over heating problem. It could be that you have a failed cat that is obstructing the exhaust flow. tap the cat with a rubber hammer and see if it rattles. Better yet, drop the cat and take a look inside. It seems to me that if this were a fuel trim problems you would be getting other codes besides the SDL. Another possibility could be a cracked header which would allow excess O2 into the exhaust. The would result in the car running rich and excess fuel being burnt in the header/cat. Again, check the cat and perhaps have the headers smoke checked for leaks.
Ketel, Park that car. Do not drive it to LA. You have a real running problem. Something is dumping fuel into bank 2 and that needs to get sorted out. Don't clear the codes. Read them and keep notes. That will give a clue. M
I was thinking the same. If you have access to a trailer or flat bed, that would be the way to get it down to see the boys so they can help you.
Mitchell - Agreed. I'm not driving to LA under these circumstances. The codes I am getting (as of this AM) are: 1448 (cat bypass flap circuit) 0432 main catalyst efficiency below threshold 1454 (cat protection active, bank 2) 1449 (cat termperature, bank 2) Seems like the first order of business is to pull the bank 2 cat and examine whether there's an obstruction or other evidence of a failure. ketel
The cat guts can break loose and clog the exhaust You would most likey here a rattle while its cold Here is a broken cat I pulled from a 355 Image Unavailable, Please Login
1st check is to see if the cat has the physical capability of being ok. Take it off the car and look and shake it. It is only a few nuts. If it is wasted then you can drive the car until the next smog check if you punch out the guts making an open tube. Later you can buy new cats or have Fabspeed recore the old for an oem look that can pass smog. Ask Peter about it. If the old cat is free flowing it does not mean the cat works to pass smog just that it won't cause the SDECU to throw codes. You need to make sure you have the capability to run right first before you trouble shoot.
You are wrong it is that simple. 1- is the car physically capable of delivering results 2- then diagnose electrical faults
1) If he cores out the CAT, he will get a CEL. (edit: another CEL) 2) The rear 02 can effect fuel trim. Yeah, I'm wrong Image Unavailable, Please Login
Hope you dont mind me strapping onto this thread just a quick question...Maybe Dave can chime in. I put flow throughs on my 355 (had a tubi muffler) I hate the way it sounds..Its like driving a Hondararri hybrid, One of the OEM cats rattled meaning its most likely bad...Would it hurt to put it back in? We dont have emissions testing here..I'm only worried about engine damage.
Oh God. Here we go again. Just get the f'in thing fixed right once and for all. If it's cats, they aren't that expensive. Fab speed can re-core the OEM cans. How can kettle still be driving it if it never passed smog? In Ct the registration would have been suspended and if you were caught driving it would be impounded.
Yup you are wrong. I never said he would not get a CEL but I know how to change that. I also never said it would not effect fuel trim but I know how to deal with that too. You know how to read the WSM that's a good start.
I don't see why all the outrage. Each owner can enjoy the hobby on his own terms. People need to chill. We are becoming more a country of extremes as extreme opinion can more easily band together to reinforce their ideas as the only right. I'll go hid now I'm sure the rocks and bottles are coming my way.
People will chill when you stop being so arrogant. To suggest Ketel is OK to drive his car 500 miles in the current condition is just bad advice. Apparently you missed the point where he posted his headers and CAT glowing red hot in the dark
Did I read this right? From Ricambi it shows cats are just shy of 8k ! $7976.00 pluss shipping to be exact...WTF?
Let me jump in here. Fatbillybob doesn't need me to defend him but, to be clear, he never said it was ok to drive 500 miles. Actually, no one did.
you guys remind me of the Siamese twins in my second grade class...They were always arguing ..My teacher would say if you guys cant get along I will separate you two!
Not outraged are all. Just really don't want to see another pizzing contest. Now lets leave the political out of this.
Evoflow cats are ~$1400. Not sure what Fabspeed's cost. Brian Dinn is or was a sponsor here, might be able to get a better deal than that. EVOFLOW
