So I'm helping a member who's struggling with some running issues... I'm wondering if his ECM went bad. I'm a little out of my element on 6E but he's been sending me run data.... I'm basically just looking at data at the moment.

In a nut shell, the car is running super rich and he can't get it to lean out to anything close to stoich.

But everytime he runs the car, it's randomly throwing a code... VSS errors, PROM errors, EST errors, EGR errors, etc.... Not sure what would cause this other than a bad ECM.

Thoughts?

The other curious

 

If it has code 51 and fans on with the key on I’d suspect the ecm is bad.

 

If it has a PROM error he won't be able to make any fueling changes. If he has a chip adapter then he MUST plugin the prom chip so the ECM sees the limp mode resistor network or it will keep throwing the PROM error code and refuse to accept any fueling modifications. I have no idea why they do this but they do.

GD

 

I had a bad ECM years ago. I came to this sight and found out how to confirm. So the ECM would put out codes, car would run like crap. Every once in a while it would start, no light, no codes, ran perfect. I took the ECM out an rested it on the passenger seat still connected. Started the car over a few days and waited for it to be running right with no codes. etc. When it did, I knocked on it like knocking on a door. Bingo, the car acted up. Got a replacement ECM off eBay and been fine all this time.

Hope that helps.