CalSpecialWV

2007 4.6 developed surging problem at idle, extremely bad when cold. Diagnosed as mass air flow sensor issue. Just handed local Ford dealer $287 for new one. Parts guy asked me out of curiosity if I had changed air filter. He informed me that he sells mass air flow sensors to K&N and other aftermarket air filter owners on a regular basis. Kind of pisses me off to pay $200 for a "better" air filter system a year ago and then have to drop another $300 today. Anyone else familiar with this issue? Is there a way to prevent? I have sent inquiry to K&N tech, will share response.

Darkvinyl

I know that K&N filters burn MAFs on VWs. Seen it often enough. Hadn't heard of it on other vehicles but I guess it kinda fits.

67mustang302

There's a TSB out by several manufacturers about oiled air filters and MAFs. The oil can come off and collect on the filament in the MAF and screw up readings, so you need to be careful to only lightly oil them(they only need light oil to work anyway). You over oil them and it will pull oil off and contaminate the MAF. You could have just cleaned it instead of buying a new one.