I've had an intermittent P303 code for the past few months. I have swapped fuel injectors, changed the spark plugs and wires, distributor cap and rotor, coil pack, and even ran a can of sea foam through it. Any suggestions on where to go from here? Why is the code only intermittent?

 

I moved your post into it's own thread.

What did the old spark plugs look like? How's the compression? If you rule out fuel and spark it could be a mechanical problem, maybe a burnt valve.

 

I had an intermittent cylinder 1 and 3 code.

Was my bank 1 o2 sensor.

 

The spark plugs looked ok to me, they had some gray ash on them, but no build up or serious discoloration. I checked the compression on the 3rd cylinder, it was about 125psi. I didn't compare it to the other cylinders or to the 3rd cylinder when the check engine light is off. I'll try to do that tonight.