So I haved searched and searched and I have to ask because my situation is a little different. I usually do all my mainance but I didn't this time. Thought I had a bad rear main seal, didn't have time to replace it myself so I took it to a shop. Ended up being a valve cover gasket. Well I told the mechanic (that I know and is pretty good) to tune it up while he had the intake off. Got it back and it had a miss. I then put OEM plugs and wires in it and change the distributor cap, rotor button, and fuel filter. Could find any vacuum leaks but it's still missing. It will read knock sensor on the scanner before it throws a code, then when it does it throws the knock sensor, multiple misfire, and two 02 sensor codes. Remember it ran fine before I took it and it only sat a week. He has went back through what he did twice and can't find anything. When sitting it may run without the miss them just start missing. When driving and it goes under load it will start missing kinda bad but you can floor it and it will eventually take off like nothing is wrong. So my question is did the knock sensor just go bad or do you have any ideas???? Sorry so long but any help will be greatly appreciated. Thanks!