Did a bunch of work car ran great til now Topic is solved

ems_kws · Post by **ems_kws** » 31 Jan 2018, 10:44

After doing a bunch of things outlined in this thread viewtopic.php?f=1&t=82491 my car ran great for a few hundred miles.

Now it is idling pretty good but under acceleration it it really rough. A basic OBDII showed codes

P0300 Misfire, at least one cylinder

P0342 Camshaft position (CMP) sensor

P0422 Main catalyst below threshold (bank 1)

I opened things up to verify the timing and it is still setting were it should. It still starts and runs so I don't think it is the Cam position sensor.

After the head gasket the check engine light came on for awhile with an O2 sensor code but that went away after driving an hour. The CEL came back on with the current codes.

Where do I go from here?

Post by **rspi** » 31 Jan 2018, 12:02

If the vehicle has VVT, it could be an issue with the sensor at the hub location. It adjust timing on the fly and if it is having issues, clogged, going bad, etc., it can cause problems and toss a code.

Post by **RickHaleParker** » 31 Jan 2018, 12:34

P0342 Camshaft position (CMP) sensor can only be one of two things, defective CMP or wiring problems.

P0342 can cause P0300 which in turn can cause P0422.

Start with P0342 Camshaft position (CMP) sensor. When you get it corrected the other two might go away.

ems_kws · Post by **ems_kws** » 31 Jan 2018, 16:41

My buddy brought over a laptop that was able to diagnose a misfire on #1 cyl. Switched the cop out with the one on #2 cyl and the problem showed up as a misfire on #2 cyl. Found the only new cop in town and after installing it everything is great.