Scanning the pcm tonight in search of my Low RPM stumble, I found a code 32, (EGR Failure) and both right and left o2 banks were reading lean (also two codes couldnt remember what they were. I know 64 is for the right bank running lean.

But question is, faulty EGR could cause a lean reading on the o2s?

Edit: also was shoing a 12.9v reading on ignition. Is that average?

Thanks

 

DTC 32 is for the electrical circuit for the EGR vacuum solenoid. This would prevent the EGR system from operating at all. If exhaust gas doesn't flow when it is supposed to, it might cause a slight leaning out of the mixture, because the PCM is assuming the exhaust gas is displacing some of the oxygen, and adding a smaller amount of fuel, but it shouldn't cause a big enough problem to cause the BLM's to max out at 25% correction and set the "lean" code.

Since you apparently have access to a scanner, use it to monitor the PCM while you are driving, and try and get the right and left BLM's for as many as possible of the long term fuel corrections "cells"... that will tell you under what conditions the problem is occuring.

 

After checking the vac lines going to the EGR the vac line from the driver side of the intake. It's a hard plastic line that slips into a rubber line. It was disconnected completely. I connected it back, and pulled the PCM Bat fuse for about an hour to reset the codes, fuel tables, etc. But for some reason leaving the key in "on" position still showed there were codes stored in the pcm. And the stumble is still there.

Access on the scanner is limited, its a friend of a friend of mine.

 

For what it's worth, when I had my EGR replaced under warrenty a few years back, I was getting a code for running lean.

Dan