I was getting error codes P0125, P1155, P0171 & P1153.
Just had the joy of replacing the front (bank1 sensor 1) A/F sensor (aka O2 sensor). This was the easy one (there are 2 ahead of the Cat), and it still took me 6 hours. If you are planning on changing the O2 sensor yourself, be sure to buy a $10 thread chaser at Autozone or other store. I goobered up the thread as I removed the old sensor, and there was no way to rethread it back.
Note: There is typically no need to replace the MAF, but you want to remove it and clean it with carb cleaner (there are multiple threads on line on how to do this)...no need to replace, just clean it along with a clean airfilter.
Cheers,
Dirk

 

I bought a slightly used OEM MAF on eBay for $40 shipped. No more MAF related CEL's. Yet, I still require resolution for P1130/P1135 as well as P0125 CEL's. The gas mileage is OK at 19.1 average but the idle seems a little rough but more importantly, the engine stutters between 25-35 Mph, around 2,000 RPM. IACV has been cleansed by the way. Any input is greatly appreciated, special thanks to Lexmex and other members for their help.