New info on bank of cylinders shut down

I had a thread that I posted the other week about a bank of cylinders shutting down on me a couple of times. Well I just had my Nouvalari exhaust put on and tonight going to try it out. 80 degrees, 9pm great night. And now for the 4th time after 10min of the car being turned on, I loose a bank of cylinders, but this time I see a somewhat dim light in the upper right (in red) blinking. I think it said "slow down 1-4", i put the clutch in to make a tight turn and the car goes silent (dead)!! I cost into a parking lot, pop the hood, wait 5min and it restarts and runs great all the way home (about 6-7 miles). I have never seen this light before - on start up or when it's done this before, but I am 6' 1" tall and the steering wheel and my hand might have blocked it in the day light, at night I saw it flashing, but it was not a bright light either. I think on start up I mistaken my 2 center green lights for my slowdown lights. I just checked and those do say Check Engine 1-4 and 5-8. My slow down lights come on when I crank the key for literally for 1 second and go out right away which is why I've never seen them plus they are way up high where my steering wheel blocks my view!

What would a blinking slow down light 1-4 mean and why would it cut all power when I put the clutch in to downshift? Also, and I might just be paranoid at this point, but there seemed to have been a whine coming from the rear when I put the clutch in to slow down to my driveway that I never really heard before. I'm sure I'm just nervous is all.
Thanks for any ideas based on this new info.
Jim

 

thanks for the feedback, I should have noted that my car is a 94 348 Spider. Not sure if my problem is the same as yours was, plus you have a 355. Not sure if a crankshaft angle sensor could be the culprit, but it is REALLY hot in my engine bay after a 15mile drive. I saw it smoking when I parked in my garage with the sun setting behind my car twice. Normally I have never seen this. Just a light smoke coming from the manifold area I think, but who knows. It was radiating upward quickly and thinnly if that makes any sense. But like my friend with a 328gts says, his engine bay gets awfully hot too and can see stuff radiating off the engine when done driving under the right lighting conditions.

 

So you just unplugged one end of the cat UCU going to the thermocouple (or would that work the same??). Are you running stock cats? I have stock cats.

 

Sorry, I'm unclear as to what to unplug. If I unplug the cat ecu from the thermocouple, then I also need to do the second plug going to the main computer as well. so both plugs need to be unplugged in order for it not to get a slow down light anymore? If I'm hearing you right I just need to unplug both of the connections from the cat ecus.

 

I'm an idiot. I have no idea where that is. I only know the two plugs that come off each of the cat ecus. The cat ecu is a flat box thingy and it has 2 cords coming out of it with connections. Those are the only ones I know. Can I undo one or both of those? Is the one NOT going to the thermocoupler what you're referring to? Sorry, I've learned a lot about what and where the cat ecu is/does and the thermocouplers, but other than that, I'm back in the dark. I do feel good about what I've learned so far and can say I feel more comfortable just knowing that little bit of info. Thanks guys!

 

Excellent, thank you!