Right I hope you guys can help.

My mate has a Bugeye 2.0 WRX, now the engine has had some issues where it pulled a shim on a lifter, now the cam has been replaced with the same cam and the engine refitted.

Now the engine runs mechanically nicely, BUT has a missfire. Now the codes that come up are CAM sensor and Idle Air Control Valve. The cam sensor has been changed for a new one, and then also changed for a known working one and still the problem remains. The timing has been checked and re checked, and it is as the manual. The wiring on the engine has also been removed and checked, along with checking the coil packs were plugged correctly.

Now the engine and all sensors were running sweet before this happened, he fitted a BR Rev limiter (despite being warned about it's dangers), and it pulled a shim then damaged the cam. This has now been removed and binned (what should have happened from the start).

So my thinking is that there is something electrical gone down, but what would cause a recurring Cam sensor problem. Could it be the wrong cam fitted, I know that the cam pulley was reused so it should be ok for the ECU.

Starting to get puzzled now.