[pfun41]

AFAIK There are no NEW EECs in production, just rebuilt ones. And Reman companies are known to fix ONLY obvious problems on their parts. So it's very possible your rebuilt EEC could have failing caps or some other iffy component that checked out fine on their tester.

 

[pfun41]

FPR was changed out in august so I’ll check the map sensor. Thanks

Don't count on an Aftermarket FPR being good. I recall chevy trucks in the early 2000s were known for having issues with aftermarket FPRs. I had one were it kept throwing a lean code after swapping in a used injection unit. I replaced the aftermarket FPR with the factory 150k mile FPR and it cleared right up. If pressure goes to where it's supposed to and clears up every time you disconnect the FPR then clearly you have an issue with pressure regulation.

 

[pfun41]

I noticed that the IAC connector harnes was a little loose. If I pushed the harness hard onto the IAC engine response changed. So I took it apart, cleaned it up, tightened it and reinstalled. No joy, truck still choked. So I decided to remove the new IAC that I installed last month and reinstall the old one. Hooked it up to the connector harness that I refurbished, and I had no problems. No choking at all. However, I'm suspicious because I'd already started the truck about 5 times trying to solve the choke issue. I'll let it sit over night and try in the morning. That'll be a valid test to see if the issue is really solved.

Never assume new parts are good. the Aftermarket is full of garbage parts these days. I've had new parts that were more problematic than the old parts. IIRC I actually have a new IAC because years ago the original was acting up, but then after cleaning the original it had less problems than the replacement.