I've a 90 Tbird with a 3.8, which began running like it was missing a couple plug wires only when cold, and giving me a check engine light after ~20min of driving.. Any time I turn the car off the light stays out for about the same period after restarting, even if it starts back up immediately.. So I borrow a code scanner, and retrieve codes for the O2 sensors being lean on both sides (41 & 91).. So I buy both O2 sensors, new plugs,wires,dist cap, rotor button, and coil. I installed everything except 1 O2 sensor which I couldn't remove for the life of me.. just couldn't break it loose in that small of a space (was hard pressed to even get the ratchet to click). So I stuck with the parts that were in, reset the ECM by disconnecting power 60secs, fired it back up, and tested again.. SAME CODES =( Well that pretty much tells me it wasn't the sensors.. return the other one and put the 40 bucks into something else.. But the car runs like a champ now, no more miss, but I still get the check engine light and same codes.. So I replace all the vacuum lines that don't disappear into the firewall on me.. no change.. egr was mounted a little loose(had to do head gaskets last november), tightened it up.. nada.. no change.. I waited until the light came on and tested without turning the car off.. same codes.. but the check engine light did go out after the test.. So what could be causing the lean O2 codes without really hurting performance much?
- posted
18 years ago