After several some what hard accelerations the engine will suddenly loose one bank. I think it is the drivers side. This was a steady issue. No CEL or slowdown light. Stop let idle, or turn off and after a few minutes the engine starts running on all cylinders and does fine. for a time. I noticed when it would happen the driver side cat and exhaust would start glowing. brighter and brighter. Due to the ECU never set a code, I think that bank is dropping off and the motor is pumping fresh air into the cat and leaning it out. Initially I swapped the ECUs from side to side to see if the glowing cat would follow. the car did not act up again. ran fine, For about 6 months. started it again. Now the driver side cat starts glowing once it acts up. Is there a common issue with grounding of the ECUs or wiring connections which could be causing this issue? I think it is likely the ECU is loosing some signal from the engine or is blanking out and that is why it is not setting a code. any thoughts? Thanks, Dan
I had this happen with my 430 once after driving it in heavy rain for almost 5 hours. (I was returning home from a long trip and had no choice.) The dealer diagnosed a bad sensor.
Cat converter glow hot meaning that unburn fuel dumping down stream and there is ignition in the cat. The cat is like a furnis, it require and operate at high temp(very hot) as hot as 2500deg. Any unburn fuel enter the cat will cause internal fire(ignition). Lean condition will not cause a glowing hot cat. There got to be Code in the system, somehow someway you have to try to ge the code or look at it soon, don't let the cat glow, melting cat and can cost you big bucks.... Misfire condition is considere primary monitor, misfire more then 3sec will trigger a code.
I believe cats will glow red in normal -- high RPM use. If you've ever watched any of the Sunday morning car shows where they have an engine on the dyno you will see them glowing red. Alan
In the context of a glowing cat WITH a "half running engine", its caused by unburnt fuel until proven otherwise in my eyes. I wouldn't drive the car too long after that or you'll trash your cats. The question is why your ignition is shutting down. I don't think its going to be a simple 10 minute diagnosis. In my eyes it might be a fuse or a ground to the ECU's or coils, the CAT ECU's cutting the ignition... or timing. First, check the fuses. Is contact good and not irregular, no corrosion. Then go to the wiring diagram and clean off the grounds in the engine compartment. I'm surprised no VISIBLE code is being put out.. I'll wager a Leonardo or SD2 will pick up a code if you plugged one in.
Gotta be a misfire of some description. Even only one cylinder failing to fire will cause these symptoms. Suggest you measure temperature at exhaust port outlets using an IR temp sensor. You should be able to figure out which cylinder(s) aren't firing properly and take it from there.
+1 for Curt and Greg. Regardless wether you have a dead ignition and or a leaky injector...The bottom line is there are unburn fuel somehow got down steam into your cat. Cat are expensive, don't get it melt or degrage its efficiency, because you will end up paying xtreme high price when it's time for you to do state smog inspection. If you have state smog inspection where you are, and if you don't have smog inspection, you are damn lucky!!! lol.
my apologies for taking so long to get back, but no time lately to get on the web. First off, thanks for the replies. i drove the car on a hot day and it took no time for it to shut down and took a while to clear up. The next few times I have driven it the temperature outside has not been in the middle of the day, and I have had a hard time getting it to act up. I did have a stored code P1269 which indicates a fuel cutout. I have narrowed my focus down to the thermocouples and their control modules. I drove the car the other day, and it took a while to get it to act up. Once it did, I pulled over, turned it off, unplugged the thermocouples and started the car up. Ran fine. I shut it down and plugged them back in. car ran fine. A couple of miles later same thing. I think one of the thermocouples are suddenly reading excessive heat and shutting down. the cats are no more glowing at that time than normal. It has been if I let the car run for a few minutes in that condition that the cats would start to glow. The thermocouple modules have the green coating. Thoughts? fyi, I do live in a state that does NOT require inspections. i am very fortunate about that.
I have a 95 F355. I had a problem for a year where car would shut off one bank out of the blue. If I turned off the engine and restarted it , it ran great. It was a bad cat ecu. On a 95 I could disconnect them without any CEL. My cats were not overheating so I was getting a false signal from the bad ecu that would shut down a bank and run on 4 cylinders. When you shut the car off it must reset. Is it just one cat that gets red or both?
If your cat is glowing then your issue is unlikely to be with the thermocouple and/or cat control module. Have you read the codes on both ECU's? I suggest you do as previosuly mentioned and measure the temperature of each exhaust header to try and find out which cylinder your problem is occuring. If you switch the coil then see if the problem moves - if yes then it's a coil, if not then look at the injector or valve.
Yes, unusual as it may seem, your thermocouples and SD ECUs actually seem to be doing their job in this instance and giving you a real warning. It is not normal to have a glowing Cat and the failure of either the thermocouple or it's ECU will not cause the glowing of a Cat. They only monitor the temperature, they cannot cause the problem.
How about taking her to someone with an SD2 so they can diagnose the problem? Quite a few things can cause one of the relatively independent banks of cylinders to shut down.
I have a good friend here with a 360 spider who just recently had a bank drop, and it was still pouring fuel into that side of the motor. His problem ended up being the throttle body itself, apparently there is some sensor or other electrical component inside the 360 TB (separate from the MAF) that went bad. His mechanic swapped it out for a spare, problem went away. If you know someone with a spare, it might be worth a swap to test if you are coming up empty on the other suggested potential culprits.
