Blkscab

Wouldn't you know, right when I'm getting ready to go through emmission testing, I get a check engine light. Codes are P0171, 0174, & 1635. So I'm running lean in both banks, but I'm not sure why the 1635 which is tire/axle ratio. Could it be that I installed 4.10 gears a few years ago & used my Excal 2 the set the speedo, cause I recently sold my Procharger & returned my system back to stock. I cleaned the MAF last week and the lean codes came back. Could that be the O2 sensors? What do you think?

pescadoman

vaccuum leak...

Blkscab

What's the best way to find a vacuum leak?

Good old Bill

Findings vacuum leaks? With engine idling, spray a good grade of carb choke cleaner on all intake joints. I prefer Chemtool B-12 made by Berryman. Other posts here talk of the PCV valve hose elbows. You will see or hear a RPM increase if the product is sucked into the intake through a faulty seal.