My impreza rs 2.5 Auto, Surges, and studdering when accelerating. It's been hard trying to pass people up. I notice that when this happen the engine is growling when I am trying to pass people up. I would litterly have to lay off the pedal. It comes and go. I have did a full tune up on my vechile three day ago. NEW COIL, WIRES, PLUGS, FUEL FILTER, PCV VALVE, AIR FILTER, IACV, AND ALL FLUID .

 

AND STILL..

 

Pulling a code of P1510, P1512, P1514, P1516 = All Idle Air control Valve circuit. throttle body has been cleaned and replaced gasket.

 

Just swapped that part out with my brother and reset the computer and this problem still occurs.

 

Any Ideas ???????

Edited May 16, 200916 yr by 2000impreza

Maybe you have a bad connection somewhere along the path.