Ok heres my problem my 99 gp gt had the plenum replaced about 2-3 weeks ago, along with a new water pump, gaskets etc. It threw up a map sensor code so i replaced it and cleared the pcm. After i shut the car off the code came back. The mechanic told me to replace the pcv valve underneath the map sensor ( it was clogged when he removed it but he said he cleaned it and though it was ok). Since the can ran fine like a dumbass i didnt imediately replace it. Yesterday during acceleration it bogged down a bit but cleared right up after a few seconds and never did it again the entire day. Today on my way to work i noticed it knocks all the time when the motor is at reg temp (though quietly) and when i rev it it gets loud quick. My question is could it be the pcv affecting my map sensor or could i have spun a bearing? The mechanic is trustworthy he worked at my gm dealership for more than 20 years so i know it isnt failure on his end.