96 3.4 popping at idle

Makes a popping sound and the engine shutters at idle. Other than the popping it runs mint. Ive changed plugs, plug wires, fuel filter, air filter (put an intake on), and pcv valve. Cel light is on and its giving me a knock sensor code. Any ideas? Video of problem---->>>>> http://youtu.be/JKz_sPuYmzY


Also my ignition has a light up ring around it and its a coppied key. From what ive seen this isnt factory?

 

The miss is not on every revolution of the engine and seems random. would a bad injector cause this?

 

Burnt valve maybe? Check your compression.

 

With a compression tester or a leak down. When i changed plugs all the old ones looked consistant.

 

Did this problem start at the same time the CEL started coming on?

 

I bought truck 2 years ago light was on at the time. It had sat for a few years as the owner has passed away. Im just getting it on the road this past week. Truck seemed to have been very well maintained and had a few maintenance sheets from a deal such as oil, filters, and timing belt replacements. Truck has 140xxxkms. The starter gave out today but when i fix tomorrow i try pulling plug wired one by one to try and find the culpret cylinder.

Also why would a burnt valve be the first choice? It does not happen all the time and will run smooth as day while in gear.

 

Not really the first choice, but you were looking for ideas, and burnt valves are common in these trucks when the valves go out of adjustment.

The CEL may be an entirely different issue, but it needs to be addressed anyway. The ECM is not receiving a signal from one of the knock sensors. Either the sensor is bad, or there is a problem with the connection from the ECM to sensor.

If only the idle is bad, I would suspect the IAC.

 

the throttle body was also very gunked up on the filter side if that tells you anything. The thought of a bad valve scares me ahaha.

 

Cat converter clogged up ladys and gentlemen. Unhooked the bastard and seems to run smooth. Really had me scared with the burnt valve comment.