P0300 Cadillac -

Question

193,000 miles checked for random vacuum leaks, replaced all 8 intake plenum gaskets, replaced PCV valve Vent Tube, replaced front valve cover Vent Tube to Intake throttle body, checked Rubber/Metal gasket between throttle body housing and intake plenum (Replaced at 115,000 miles), car idles roughly, stumbles on acceleration, disconnected Camshaft Sensor, then p0340 code showed immediately. The Coil Packs are next, however they show different GM Part numbers for "front" bank vs. "rear" bank. Any idea's how to diagnose which Coil Pack could be at fault?

Answer 1

Hi there,

Since the car is idling rough you could start it and disconnect one coil at a time. If the engine runs rougher, plug it back in and move to the next one. When you get one that doesn't affect the way the engine is running, replace it.