I cant figure it out..It stumbles as i let the clutch out and Lags hard in WOT. I have cleaned the MAF and ACT sensors, replaced the PCV valve and all i run in i t is 91 octane fuel. Maybe i should replace the fuel pump and filter..i dont know if spark plugs make all that much difference.
if you haven't in a long time maybe an all out tune up in due. change the egr, fuel filter, plugs, wires, O2 sensors, cap and rotor, ignition module, the usual oil and oil filter change. there should be more, that i missed. someone else might help.
Recently my car acted like that... Before you spend money like i did time it and see where your at. I spent a few bucks just to find out somehow i lost 20 degrees of timing. But that might be worse when i find out why... (which im sure i will )