Typically, the factory oil on the filter does not come off. But that don't mean it wont. Give the MAF wire a cleaning just to make sure. Do not touch the wire.

I hooked up the meter and I had two codes;

Both are PO420 Catalyst is below threshold Bank 1.

Take a look here and see if this helps. https://www.gmforum.com/t284086/#post1390979

Problem Solved.
I put in a new O2 sensor after the Cat and replaced the rest of the vacuum lines. Car runs good and the gauge was reading 27 mpg average on the highway this afternoon. This is about 4mpg higher than what we have been seeing over the last few years.
Thanks to everyone for their input and help!
I now how have this problem and the electrical problem resolved. I have a vibration problem but will start a new thread.
-Mike-

Good to hear. Always like to hear about members that have corrected the problem and have a healthy happy car again.

How did you get the O2 sensor out. I can get a wrench on it, but not enough leverage to break it free.

I changed it while the exhaust was hot and I sprayed it with liquid wrench and let it soak.
With a 12" 22mm wrench it came out with a good tug.
I had a hammer on stand by but did not need it.