Originally posted by Alquistador:
I did have a p0171 cel. Bank one lean. I reset the computer and the cel has not come back. It's been 4 months. I am going to replace the downstream sensor and take if from there. ...


You will be wasting your money. P0171 is not for a defective nor "lazy" ("slow") downstream sensor.

http://www.contour.org/ubbthreads/showflat.php?Cat=&Board=trouble&Number=1111728&Forum=All_Forums&Words=1004&Match=Username&Searchpage=0&Limit=25&Old=allposts&Main=1111728&Search=true#Post1111728

Edit.
These are codes which could be for "slow" ("lazy") O2 sensors.

HO2S slow response rate - P0133, P0153
HO2S lack of switching - P1130, P1131, P1132, P1150, P1151, P1152
HO2S lack of switching (sensor indicates lean) - P1137
HO2S lack of switching (sensor indicates rich) - P1138

and even some of these could be attributed to other issues too. But definitely, a new downstream O2 sensor isn't going to solve your P0171 code problem.

http://www.v8sho.com/SHO/TSB0197HO2SServiceTips.htm

"Always do the cheap and easy ones first." 1996 V6 ATX 96K miles