i have the codes for the two upstream sensors as well (p1131 & 1151) and some days the car absolutely refuses to idle right with a slight decrease in mpg as well. i am replacing the offending sensors, cleaning the maf and intake manifolds and checking for vacuum leaks. from what i understand that should just about take care of things.

00 black/tan svt, #2052 of 2150, born 2/1/00 formerly known as my csvt "Nothing in the world is more dangerous than a sincere ignorance and conscientious stupidity." -Martin Luther King, Jr.