Intermittent rough idle

[89armygt]

Hey everyone! I have been having an issue with my car for a little bit and I wanted to see if anyone else has run across this problem. At random times when I start the car it run like it had a cam in it. First time it happened it threw two codes P0340 and P0344 with a CEL. Turned the car off and back on, runs fine. After driving for a bit the CEL went away. Took it to the dealer to get it looked over and they couldn’t find out why. Month or so goes by and boom pops up again. Didn’t shut the car off and drive straight to the dealer to get a computer hooked up to it. Same codes but also says misfire. Not misfiring though cause while driving it’s fine. Just when it gets to idle is when it runs like crap. They replace the sensor connector and was fine for a few days. Last night it happened again but dealer was closed so couldn’t take it back. Any input would be greatly appreciated if anyone has experience with this. Thanks gang!

 

[jvandy50]

Have you recently had any work done?

 

[89armygt]

Nothing engine related. I changed the oil at 5k miles and added a catch can. I know those have nothing to do with the problem. Issue happened before anything was changed on the car.

 

[cobracide]

Maybe swap the crank sensor out for the hell of it - if it isn't too much but It's probably wiring gremlins since it's intermittent and those can be the toughest to isolate. PCMs are pretty reliable and expensive so that would be the last thing to check via diagnoistic/swapout.

possible causes:

• An open circuit within the wiring
• A failed powertrain control module
• Grounded, broken, or shorted wire or connector in the circuit
• A damaged or failed camshaft or crankshaft position sensor

https://www.autozone.com/diy/diagnostic-trouble-codes/p0340-camshaft-position-sensor-circuit-malfunction

 

[jvandy50]

Nothing engine related. I changed the oil at 5k miles and added a catch can. I know those have nothing to do with the problem. Issue happened before anything was changed on the car.

gotcha. 2 things that caused a misfire on mine were the crank relearn process after motor swap, as well as the 2 sensors on back of intake not being plugged in. didn't figure that was your issue though

 

[89armygt]

Dealership got back to me yesterday. Cam position sensor. The mechanic said he swapped the sensors around and was able to get the car to duplicate the issue and DTC to move to the other bank.

 

[tampasnake]

Thanks for coming back and updating the thread with the resolution. I have been done so many rabbit holes searching threads over the years that never get updated with what the fix was.

 

[89armygt]

Well I though my that was the last of my worries. Lol. Got a CEL with a misfire on 4. Swapped coil packs and changed spark plug. Stayed with the same cylinder. Ended up being lost compression bottom end issue. 10k mikes on the car. Brand new motor being installed now. Thank goodness for warranties!

 

[tampasnake]

Oh wow that is a major difference than just a cam sensor. This is good information to keep in the back of my mind as well. Thank you for the update!