Are any codes present? Also, have you checked fuel trims? Based on what you mentioned regarding the exhaust sounds like it is extremely rich. Also, are there any strange sounds from the catalytic converter indicating it could be partially plugged?
Check the short-term fuel trims. I have a feeling it could be related to a stuck fuel injector. Also, check to see if there are codes present. I have a feeling you won't need this, but here is a video showing how to retrieve codes:
One last thought, if you do a fuel pressure test, watch fuel pressure drop off to see if it drops too fast. That could indicate an injector issue.
Let me know.
Wednesday, April 21st, 2021 AT 6:57 PM