have you tried resetting your ecu?
I had both headers leaking near the H-pipe, (they had holes from rust) while I don't remember it making the idle really erratic, it did cause a slight hunt at times. What happens is, the exhaust stream pulls outside air into the exhaust, and past the O2s. The O2s smell this outside air with it's oxygen molecules intact, and reports to EEC that the motor must be running lean. EEC responds by injecting more fuel. So you'll have a car whose exhaust smells richer than Bill Gates, yet EEC tells you it's running lean.Treachery said:Question:
Can an exhaust leak at the header cause this strange behavior with the idle?
True, no illumination of the check engine light, but, were you to have scanned EEC, you would have pulled some codes. Also, were your O2s disconnected when you did this? That would make a difference, although, I would think that you woulda gotten a light.jerry_dawg said:Scratch that whole thing about exhaust leaks and idle. I ran mine for a whole day on open headers and no problems, no check engine lights all day. Neighbors loved it.