ja9333

I have a 97 legacy that is throwing p122(tps) p303(cylinder 3 misfire) p325(knock sensor). I replaced the tps, spark plugs, plug wires, #3 injector and still throwing all 3 codes and no improvement. 230,000 running ruf, lacks power, shimmy. figured the knock sensor was due to p303 but i cant seem to determine what the cause of p303, also why am i still throwing p122 after the tps has been replaced. any ideas or suggestions would be greatly appreciated thanks for looking. im running out of money for parts and don't know what to check next.