Well stock gsr have been throwing this code for a couple of months now. Sometime it will come on and sometime it will dissapear for a couple of day. Well today me and my friends decided to figure out what was the problem. We check spark plugs, spark plug wires, distributor, valve adjustment, and finally a compression test.
The compression test reveal some gruesome number. Cyl 1 were around 150, cyl 2 at 125, cyl 3 at 90, and cyl 4 at 120 something. What do you guys think the problem is? Pistons? Valves? There are no oil leak, oil burn, or any noticable problem. The cel light come on only when the engine is misfiring, and if you place your hand on the exhaust end you could feel it push your hand away then pull it back in. Whenever the cel goes away the car run fine and there is no misfiring. Any help or comments would be appreciated thanks you.