Someone please help me. I have been trying to fix this problem for a long time and can't figure it out. If I drive my car for awhile and let it get up to operating temp and then turn it off to get some gas or something. Ill try to start it up again and it idles low and stalls a lot. I recently replaced my timing chain about three months ago and that seemed to fix the problem but its back again. I have also recently replaced my fuel pump and O2 sensors. If I start it and try to drive it it backfires out of the exhaust really loud. The only way to get it to stop is to rev the engine to about 5 or 6 grand.