What has prompted you to check the post-cat O2 sensor?

It isn't all that difficult to get out, but I wouldn't remove it unless you have a code specifically pointing at that sensor...

 

Well, I had the code ran again which prompted the same code, P0175. The guy working said that it was coming from "Bank2" which was the O2 sensor after the cat. Whether he was just running his mouth, I don't know; however, it would make sense that the catalytic converter wouldn't be catching everything which would gradually create build-up over that O2 sensor. This would lead me to believe that the O2 sensor merely needs to be cleaned.

I'll wait on that though and see if cleaning the MAF sensor eliminates the issue. I'll update soon.

 

P0175 - Fuel System Trim Rich Bank 2

Well, this doesn't point out an O2 sensor fault and definitely doesn't have anything to do with the post-cat sensor. Your '99 will have 3 O2 sensors. B1S1 is the driver's side (bank 1) upstream sensor directly behind the driver's side exhaust manifold on the y-pipe. B2S1 is the passenger side (bank 2) upstream sensor directly behind the passenger side exhaust manifold on the y-pipe, directly ahead of the 'Y'. B1S3 is the post cat sensor in the 98+ configuration and is for catalyst monitoring only, having nothing to do with engine management. For the '95 to '97 trucks, there is a 4th sensor B1S2 which is the pre-cat catalyst monitoring sensor and again, it has nothing to do with engine management.

Start by visually and physically check the following items:
* The air filter for being restricted
* The air duct for being collapsed or restricted
* The MAF sensor for proper installation and any screen blockage
* IAC: if a low or unsteady idle is being experienced
* Check for throttle body coking or objects blocking the IAC passage
* Bank 2 HO2S1 electrical connector for contact with the exhaust system
* Check the fuel pressure regulator for proper operation or a slow diaphragm leak
* Excessive fuel in the crank case. Change the oil if necessary.


Hope this helps!

*EDIT* - I did have a diagnostic procedure here, but the formatting was messed up and I lost it.. I give up.

 

Well, I appreciate everyone's input.

This weekend, I removed the MAF sensor and cleaned it. (It was a little dirty on the filter side) I then re-installed it and reset the computer.

Everything has been running great since then. Thanks again!

 

same problem i had. hopefully it stays :P