Friday, May 16th, 2008 AT 1:22 PM
The car runs great, but when you first start out when the engine is cold the car wants to stall when you give it gas. It doesnt die and will slowly climb in RPM and then when it hits 3500 rpm it just comes alive. You can feel the engine "hunting" a little until it warms up and then it runs like a top. The check engine light comes on and stays on and the only codes are P0170 and P0171. Occasionally the light will go out for a couple of days and then its back on constantly, right from start up. When I reset the light it will come on right about the time the engine reaches operating temp (about3-4 miles of driving). I have replaced the fuel pressure regulator, spark plugs and wires, dist cap and rotor, pcv valve and cleaned the IAT (lots of crud), cleaned EGR as well. I've done the Seafoam treatment too, multiple times, and cleaned the throttle body. I've have soaked the engine with ether looking for a vacuum leak and replaced the gas cap. Once the car warms up, it runs like new with the exception of the check engine light. Problem still there, any suggestions. Do the two problems (cold running condition and dtc) seem related with a common cause or are they most likely 2 separate problems. When does the oxygen sensor actually come into play? If it is ignored in open loop, then what would cause the hunting/stalling problem? HELP PLEASE!


