I have spent that last several days combing over this site and google and it seems that these two codes have numerous aliments.

I changed the oil, spark plugs and oiled my air filter at 90,000 miles on my 04 Z convertible. After I noticed the oil in #6 I changed the valve cover and gasket on the drivers side.

I started it up after completing all the work and ran fine for about three or four minutes and it started rough idling. Started checking everything to make sure I didn't have a leak and nothing was found leaking to cause such a rough idle.

Drove it to Oreilly's Auto and had them scan it codes. (I have a small reader that only gave the two codes.) Guy tells me that there are 11 codes. Break it down and several were repeat codes I was told. One was the Transmission Control Module, why would that cause a rough idle?

Anyways, the main ones are the P0011 and P0300. Researching these codes has been a headache as there are so many different causes it seems.

So I am asking if someone can help me in determining why I have such a rough idle? The car is stock except for a Injen CAI.

Thanks

Flipper

 

Begin with an idle relearn procedure first first. When have you last replaced your throttle body unit? If you never replaced it, it's at the end of its life expectancy.

 

Do a ecu reset, throttle body and accelerator pedal position relearn. Could also be too much oil on the filter getting on the map sensor.

 

Thanks I havent changed the Throttle body. Wife bought me the car when I retired early. with 29000 miles on it. It has been a great car so far. debating going LS swap.

Will do the idle relearn and ECU reset. I had the battery disconnected throughout the whole process. Will look up the relearn process for the idle now.

Thanks again.

Flipper

 

Instead of an LS swap, why not just build the bottom end and add boost. The manual relearn procedure is kind of PITA but if you know someone that has a consult device they'll be able to plug right into your OBDII.

 

Done all the resets and still having the same issues and same codes.

Rough idle but seems to run fine on the road. Only have drove it 12 miles to see after resetting ECU, Idle and Throttle position. Same codes showed back up again. P0011 and P0300.

scratching my head wandering what to do with this dang thing.

 

Since you're oiling your air filter, start by cleaning your MAF sensor. That costs hardly anything and at least eliminates the possibility that it's the reason for the misfire code. Do a live scan on your O2 sensors from open to closed loop as well.

RE: P0011, CPS failure is fairly common on these cars. Make sure you're getting a good reading on the sensor, and if not, replace it.