For over 6 months I have had error code P0172 "System too rich (Bank 1)". About once a month I erase the code. It comes back within a few days, and I again erase it later.

Today I went to town and when I pulled into the parking lot I could hear ahigh pitch sound that was almost inaudible. When I came to a complete stop I noticed the CEL was flickering.

When I returned to the truck 30 minutes later and started the engine it would die. Istarted it again and was able to keep it going by giving it gas. When I backed out of the parking space it died again. Restarted the truck and entered the highway. I then noticed the CEL light had gone out on it's own (it hasn't been erased by me for a month)When I arrived home the truck seemed to be running perfectly! Restarted the truck and it idled fine.

Could it possibly be that somehow it corrected the P0172 problem on it's own, and the dieing problem was that the computer was trying to adjust from the rich system it was used to,to match a normal mixture??