Do the compression test. You might have bad rings or valves, or a hole in the piston...

 

The P03000/301 are causing the hard shifting and all of the other symptoms you cited. As soon as that is fixed all will return to nice. Most "performance" codes turn the traction control off and put the computer into open loop mode.
You need to do a compression test and look at the timing chain; ANY slack between the cam sprockets is bad.
Misfires are rarely spark related, unless you don't use ACDelco 41-103. A tune up is replacing the plugs at 100,000 miles and cleaning the throttle body and MAF.

 

thank you for responding. I pulled the maf cleaned the contacts, pulled the throttle body it definitely needed a little cleaning. Cleared the codes. Plugged everything back in drove it 50 miles. Shifts smooth as butter, no more cel/ tc. It used to have a rough idle that is no longer apparent and I gained 8 mpg.

I’m hoping its a solid fix, I appreciate everyone’s suggestions and input.

 

Thanks for your follow up and feedback.

 

Codes clear themselves when fixed. When you clear them ALL of the OBD2 testing starts from scratch, some take 2 weeks to run.
Don't clear codes unless you know what you are doing, the CEL is not the problem it is the cause of the CEL that is the problem.

 

Now yer making me feel guilty. I don't ask. I just slip the Bluetooth dongle in as I get behind the wheel. When I pull out my phone, they think I'm checking for messages.

But you raise a good point. Asking and getting a "no" might be a red flag. But it also might be that the owner is clueless and paranoid about hurting the car. New policy. Slip the dongle in and screenshot any codes. Remove dongle. Ask permission. In that order.



So much great advice here! EVERY SINGLE reply was accurate and useful. Same question at Farcebook, EVERY SINGLE reply might be useless or wrong. Best case, maybe 25% accurate.

 

Or, gone off on "don't buy this buy that" and never get an answer to the question. Leaving people in the future with a waste of time search.