My IAC seems to be goin bad or is bad, my engine's idle is slightly unsteady it goes up and down, when i put the car in gear the engine seems to choke a little bit and then sounds normal. my cars pick up comes and goes, it never was like this, my mileage is down, i have a friend who is a mechanic and he points to the Idle Air Control valve, any ideas? My car seems to be burning oil as well, maybe i also have a valve gasket leak.

 

might be a throttle position sensor. located right on the throttle body, if it's off it'll cause an unsteady idle and bogging under load.