I am a new member but have been reading the fourms for a long time but finaly could use some help.
I had to install a New oil pressure sending unit which fixed my oil presure problem but when i was removing the air cleaner box I ended up breaking the box because the previous owner had gluded/siliconed it to the throttle body I just could not get it off.
To fix the problem I figured it was a good time and reason to upgrade to a new setup. Installed the 14x3 round filter setup but now the check engine light is on. I did the turn the key on 3 times and came up with the code 51 and 21 it seems like its giving me two codes. What can I do to fix this? Is this a result of putting the air cleaner on?
Thanks, Kevin

BTW- Its a 96 1500 4x4 5.9

 

21 - O2 sensor does not detect rich or lean condition, or O2 sensor input voltage too high. DRB will indicate which side with dual sensors. The O2 sensor signal should fluctuate under normal conditions.

51 - O2 sensor signal indicates lean air/fuel ratio during engine operation. The computer ran the mixture to the rich limit of programming, but the O2 sensor still indicated a lean condition. L or R indicate left or right side O2 sensor. Fuel pressure problems can lean the mixture and set this fault.


Normally I would say swap back to the old and see if the same problem exists. Try resetting your pcm and see if it comes back. If it does, looks like the obvious, an o2 problem like the codes say.

 

I tried resetting it but it came back with in 20 miles. I would just go back to the stock setup but its totally broken. Do you think new O2 sensor would work. The bad part about all this is i have a 750 mile trip coming up on friday and need to renew my inspection. I know it will not pass while shooting a code and its already about 2 months behind so dont want to travel across 5 states with expired sticker. Short on time so all help is appericated. Thanks Kevin

 

Someone else may be able to chime in, but like I said if it were me I would swap back to the old. Seeing that that isn't an option... My next plan of action would be to replace the front o2 sensor. It is a $50 dollar guess, but its the best I can offer. You can rent the socket from autozone if you have one near you to remove the old o2 plug. Wish ya luck.

 

Yeah, I say throw in a new O2 and see what happens.

 

Yeah may have to try it. Also once fixed will the light clear its self or will I have to have it cleared. If I understand correctly if you clear a code by disconnecting the battery that in its seld will send code that will not allow it to pass.
Thanks, Kevin

 

it won't remove the light right away... Usually you would reset it, and then drive like 50 miles before getting inspected.

 

Seems like someone would have had this problem before since so many people have the round air cleaner setup. Has anyone else experienced this problem after this mod?

 

I have ran the cold air intake and currently using the 14" round with no problems.

 

Would changing the air cleaner suddenly make the O2 quit working correctly? I know one thing this is being a real thorn in my side. I have to get this fixed one way or anther in a short amount of time and a low budget.