Cold weather

Cold air intake is drawing in to cold of air

Dump the codes and see that the computer thinks is wrong. Codes may be present even if the Check Engine Light isn't on.

See the "Surging Idle Checklist for help with all your idle/stall problems. You can guess at the problem and throw parts at it, or you can use the checklist to help you find the problem quickly and inexpensively.

The quick and easy way to dump the codes is in there too, and all you need to do it is a paper clip! The first two posts contain all the fixes & updates. At last count there were 24 possible causes and fixes for surging idle/stall problems. I continue to update it as more people post fixes or ask questions.