GM again has put out a new TSB related to buying 3rd party airfilters for like $300-$500 that claim 30 HP gains (which is BS)
in that, using a washable airfilter requiring spraying it with oil because the pores of those filters are large which sucks crap into
the engine
In countless cases of doing custom tunes I could see screwed up fuel trims and airmass reported was not normal

That is because they use the oil to try and trap dirt but in doing so over oiling the filter the excess oil flows across
the MAF internal sensors and causing the airmass output to be incorrect and PCM is commanding fuel injectors to the faulty values
this also affects auto tranny as to line pressure

If using such filters assure it is not over oiled, less is better and make sure you give it time to dry some before installing
But in any case, if the vehicle is in GM warranty period, and they find you're using an oiled filter, kiss off any damage costs done and void warranty for that

Attached Files Donotusefilers.jpg

Team ZR-1
True Custom Performance Tuning