Car hesitates under hard acceleration

[GTLGDP]

That's what happens every time i get on it. It's very annoying and makes my car very slow also. Its fine when I'm driving normally, or if i give it sort of a half throttle acceleration. But when i get on it a bit harder, it just hesitates. It's especially bad when I'm going around 40mph and i slam on the gas, i get practically nowhere. I have a knock sensor code (P0327) so i don't know if thats the cause, or maybe bad spark plugs, or maybe exhaust leak. I just don't know where to start. I recently replaced the EGR valve also, but the code hasn't gone away yet nor has it been cleared. HELP

[sdogg201]

To clear codes simply disconnect the negative cable from battery for a minute or so. Look for vacuum leaks (spray some starting fluid around the intakes ect) a tune up might help as well faulty spark plug wires. those are the things I would check first. Also for some reason I have seen coolant temp sensors do weird things to engines.

[GTLGDP]

The previous owner said he changed plugs and wires..but you can't trust anyone. Any other ideas too?

[sdogg201]

Yea I would start looking at the lower intake manifold may need a new gasket. common on 2 piece manifolds to leak after many miles. I agree you can't trust anyone unless they can back it with receipts. Could look into cleaning the MAF (I would clean all sensors) and see if that helps.