I'm curious if anyone has had issues with not passing smog, using O2 sensors from an auto on a manual truck or vice versa?

I just failed, high NOx at 15mph 1750 (max allowed 508) everything else was pretty good. I didn't even look into if they were different for different models. I've ordered the correct front O2 for my configuration. Still not sure if this would be the problem, figured it would be good start. My friend is going to pre-test before I go back to the ref.

 

I didnt change O2 sensors but I changed ECM's from auto to manual and it passed as both. First an auto and then a manual.

Not sure but I would think that they would be the same. I dont have any codes so both ECM's must like them.

 

3.4's shouldn't matter. There is a different part number from manual to auto, but the only thing I could tell is that the pigtail is shorter on the manual tranny versions.

Now if you kept the 3.0's in place of the 3.4's?? Not sure about that.

 

I've ordered both sensors because they are the correct ones. I think the front o2 maybe my problem. I've read up and it sounds like the front o2 may degrade over time causing a leaner mixure which maybe causing my problem. A new airfilter and plugs may help too.