Camshalft Position Sensor code P0340 popped up on our 4.2L a while back. It started running poorly, stalling, jolting under acceleration, etc...

It was fairly soon after spark plug change where I instructed my nephew to put in MC plugs only, he came home with NKG... Gapped to .050 (these 2 things alone may be my issue but maybe not)...

We changed the sensor out and it ran great for one trip, no code or anything.

Next trip, back to the same... We since then unplugged the sensor and it runs ok in 'safe mode' but will jolt under moderate acceleration at times.

I have been watching the alternator voltage with a scanner, stays at 14.5-14.8. I still may have autozone test the alternator just to rule it out...

I will have him swap over to MC plugs gapped to .054.

We can't see any issue with wiring from PCM to sensor...

What else could we look for? The jolting under load makes me think fuel pressure, maybe?

We are stuck on the "code of death" LOL Any help appreciated...

Thanks

 

Ngk's are good plugs. Check the connector on the wiring harness. They get oil in them overtime. Also a bad pcm can cause it. Have it scanned with a high end scanner an see if a P0600 shows up. Also reset KAM.