Codes P0122, P0304 and P0122?

Hello,

P0122 - Throttle position sensor (TPS) "A " circuit.
P0304 - Misfire cylinder 4.

These 2 codes do not seem to be related to each other.

P0122
I would suggest first checking the TPS connector. Ensure that there is no corrosion, and the pins are in good condition. The TPS is located on the side of the throttle body, image 1.
It has a 3-wire connector.

Pin 1, blue wire TPS signal back to PCM pin D14.
Pin 2, pink wire 5V power supply.
Pin 3, black wire ground/low reference.

Using a voltmeter, you can check 5V supply and ground, also check signal wire back to PCM.

How to use a voltmeter:
https://www.2carpros.com/articles/how-to-use-a-voltmeter

How to check wiring:
https://www.2carpros.com/articles/how-to-check-wiring

P0304 - misfire cylinder 4.

This is the cylinder closest to the transmission side.

How to check:
https://www.2carpros.com/articles/symptoms-of-engine-misfires-a-step-by-step-guide
and
https://www.2carpros.com/articles/engine-misfires-or-runs-rough

Cheers, Boris