No codes other than poor converter efficiency. I need your recommendation. I used fuel system cleaner in the fuel about a week ago. I think I have narrowed the problem to trash in the fuel lines breaking loose during warm up, because it only stalls during warm up. After that it runs great. I have watched your videos and checked everything I could find that would cause a vacuum leak. I just now finished monitoring high pressure when it was stalling. The pressure went over 1500 psi then dropped to 400 psi when running good. Then I stopped and took off at full throttle. Pressure built up as engine and speed increased. This is a 2.4 ecotec engine. 170000 miles. Automatic transmission. Thanks for your help.
No, I'd have to see in person to do a bunch of tests, but you do have inefficient cat. I would first pressure test the catalytic converter by removing oxygen sensor in front of and putting a pressure gauge in. If it's building up too much bag pressure. That is your problem and that's very typical with that kind of mileage. It could also be anything with the high pressure fuel pump. Lots of things can do it, but if you have a cold you'll always start by working around the code first
