-3vze- 94'
I got this truck about 2 years ago and have had this trouble from the get go. When i first got it the nok sensor was bad and the dealer replaced it and the o2. Since then i've delt with the 25 code but didn't think much about it. The power was about 90% but i really can't compare it due to it never being 100%. It's also got 33's so i figured the 12-15 mpg was normal. However now that i need to register it, it will not pass emissions. The HC and CO% outputs are through the roof. It's running very rich. But the code is the Lean code?

I changed the o2 and re-tested....no change.
I have since changed the ECT sensor, reset the codes and drove about 100 miles. No noticable change in power and then the same code tripped.
I am in the middle of changing the fuel filter and if that doesn't do it, i was thinking of changing out the cold start. But before i do i wanted to get some advice about the subject.

Anything would be helpfull, thanks

 

did the cold start sensor solve the problem?

 

I see you said you changed the sensors but did you ever check to see if the wires are any good if they are broken or coroded the circuit would be open and not transmitting a voltage to the ecu this could be your code you could check with a multimeter just attach your leads to either end of the wires and check for continuity most meters have a setting for this it should make a tone when a connection is present also move the wires around as you are testing to see if they are intermittent or broken. just a tip some alligator clips on your leads will make this alot easier. keeps the hands free.

 

turns out after changing all the sensors i could, I found the problem in the wiring. The o2 sensor wires next to the block were rigged and taped. Needless to say after cleaning up someone's crappy handy work, I got it all running great. co2 levels are 0.

 

hey, where is a good place to order a obd1 scanner? i need one for my truck. i have the same truck and the same motor. i have a check engine light comin on intermittently and it will lose a little power and i can turn the truck off then on again while rollin and it will reset and run right again for a while. im lost man. any help would be great.

 

you dont need a scanner to pull codes...read http://personal.utulsa.edu/~nathan-b...85diagnosi.pdf gives an easy to understand explanation of how to pull codes, and gives the meaning of each code.
....and i bet my left nut you get code 71!!egr

 

what do you reckon i need to replace in it?