hey y'all newish to here. i have read multiple threads from here with some great help and guidance. i have a 94 e320 3.2l. i recently changed the plugs wires coils and maf due to a bad idle/misfire. maf seemed to help the misfire/idle. my car still wont go passed 3k rpms i have the code reader and have read and deleted the codes a few days ago with no luck of anything changing. when i first got the car it ran flawlessly. now it wont go passed 3k in drive. in park/neutral it revs perfectly but has no get up to her anymore. i have a o2 sensor on the way. broken vac line im gonna fix tomorrow. after replacing maf today the cat was making a rattling/knocking sound. cat has been replaced and is barely a month old. could it be a bad cat? plugged fuel filter? bad fuel regulator? renaissance valve? throttle body? (have a used one out of 95) can anyone point me in the right direction? any help is greatly appreciated!!!

Robert, if you don't know when the fuel filter was replaced last, replace it.

If you are unfamiliar the fuel filter is under the car in front of, and slightly inboard, of the right rear tire. A black cover protects the fuel filter and fuel pumps from road debris, and is secured by 10mm fasteners. Temporarily clamp the rubber fuel line while changing the filter, or you will have gas draining from the tank.

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Fred Hoelzle

Where did you buy the cat? I had the same problem my cat also was a month old.