i have a 98 dodge dakota slt. i have taken the v6 out of it and dropped a 5.2l v8 in it. it also came out of a 98 dakota slt. i swapped the motor transmission transfer case both wire harnesses under the hood and the one in the dash also the brain. i have managed to take care of all the little problems except for one. i have a trouble code a p0171 lean condition bank 1. ive changed out both o2 sensors map intake gasket plugs wires i even took the headers off to see if that would help. i have also spayed several cans of starting fluid checking for leaks. no matter what i have done i can reset the comp. take it out for a drive it runs great until the comp sets then my check engine light comes on and it starts over loading and runns rough. i get back i check the codes and i keep getting the p0171. thats the only one that keeps coming up. im about out of ideas im hoping someone might be able to help me out. thanks for your time

 

Have you plugged any kind of scanner in to read the O2 sensor outputs? I use the Ultragage.

 

yes i have both o2 are working

 

Only way it knows bank 1 can be lean is if the pre-cat (upstream) sensor is throwing a lean signal. Should be able to see such a signal on the OBDII scanner.

Since you say you replaced both O2's, I assume your truck does not have the mini-cats on the manifold, just 2 pre-cat O2's on the manifold and one after the main cat?

 

I have an o2 just before the cat and one after the cat