My service engine soon light just came on, I have a X-CAL 2, so I plugged it in and read the code. It says P1507 IDLE AIR CTRL UNDSPD ER can someone please tell me what it says. I have a feeling it has something to do with my mass air being I just cleaned it.

 

that indicates and idle air control problem, your iac valve is hooked up to your throttle body make sure all connections are tight. same thing with the maf, make sure that you plugged everything back in correctly. is the idle speed lower than what it normally is? you can try pulling off the iac and cleaning the valve with brake parts cleaner, letting it dry and plugging it back in.

good luck.

 

under speed would make me thing that either its unpluged or you need a new one. id do like laserred said and pull it off and try cleaning it first. then clear the code and see if it comes back. its screwed on w/2 bolts. its mounted right behind the tb on the back side of the upper.