Ok guys, here is the scoop.
88 3.0 auto fresh TPS and HG a few months ago. Also replace all tranny solenoids and replaced a malfunctioning ECU.

Over the last few months the Check engine light periodically came on but when I shut truck off and restarted light would stay off sometimes for a few miles, sometimes for a day, sometimes 3-4 days. I finally pulled the codes and got a 22- Coolant temp sensor. I replaced that Saturday. Then Monday CEL light comes back on, I pull the code and it is 21-oxygen sensor. So I replace that last nite.
Today I drive about 20 miles and the truck seemed to be running smoother, then the damn Check light came on again!

So I pull the codes and I am getting 3 different codes:

25 - Air–Fuel Ratio Lean Malfunction
26 - Air–Fuel Ratio Rich Malfunction
51 - Switch Condition Signal

Is it logical to get a 25 and 26 at the same time? Seems odd to me.

Most importantly, what can I do next to fix this once and for all?


thanks

Mark

 

got same prob. 88 3.0 w/ man, cel came on and truck slowly started getting worse, lugs really bad in lower rpm range, wont idle. codes are 25, 26 and 51. 51 is ac something so i didnt care but its strange yopu got same codes. im replaceing the o2 sensor tommorow. need to tap the o2 holes. let you know how it goes. btw anyone know where the fuse to reset codes is?? one other quick question, looking at putting winch on, is a 6k rated winch gonna be ok for MINOR recovery or should i go for the 9K? only reason id go for a 6 is weight...