Sigma86

Hey guys, just rebuilt the heads on a 99 camaro ss ls1. Put everything back together in hopes of starting it right up but the car idles very poorly and I literally get no throttle response I will put the pedal to the floor and rpms won't budge. Hooked up the OBDII and said I had P0108 Manifold MAP Sensor High Input and P0342 Camshaft Position Sensor A Circuit Low Input codes, I figured I can replace the MAP sensor and get away with it but that's not the case, it still idles like crap.

Anybody had any issues with the P0342 code? I can't figure it out..

BackNBlue

Did you unplug the cam sensor when you did the heads? I would say check the connection and the harness to make sure it didn't get damaged somehow? Also make sure the ground straps are all back on the motor and that they are clean and tight.

Sigma86

No, never touched it in the back. It remained connected the entire process. But it was throwing this code before I tore down the motor.. but my problem wasn't that but now it is and the car can't even hold it's idle.. I checked all connections they are snug and secure. Would the Camshaft Sensor be effecting the idle? I read the MAP sensor is usually the cause of all the symptoms too however I replaced that and nothing changed.

Sigma86

Turns out the Camshaft Position Sensor was all my of nightmares. Now fires up on start and back to normal lope idling. For anybody with the same problems it's a tough call unless you have a OBDII, I had both MAP sensor and Cam sensors giving me codes and they both have similar symptoms.

BackNBlue

I think they may share a common power source or ground (or both) so if one goes out it can affect other sensors on the same circuit and they will all throw codes until the problem one is fixed then the others return to normal.

Sigma86

Ahhh okay, makes sense because the first thing I actually checked was the MAP sensor with a multimeter and was showing 1 volt.. but I ignored the CMP thinking it could just be the MAP sensor. That was ruled out quick. All good now though!