car is running poorly and wondering if it might have something to do with a lean or rich engine.
How can I diagnose this so that I know I am in the right direction and it is not one or the other?
I’m trying to avid testing map sensor, looking for vacuum leaks, investigating fuel system etc if I can just know by looking at some other parts of the car. I take it a check engine light does not always accompany a lean or rich engine?
Thanks.