I have a 2000 volkswagan beetle... 2 month ago ...my engine light came on ... the code P0302... cylinder 2 missfire.. i changed all the spark plugs and everything works fine... now my engine light came back on ... P0303... cyclinder 3 missfire... it cant be that fast ... i jusht changed my spark plugs .... can it be something else?

James Williams

• 115 Answers
• Posted on May 21, 2009

SOURCE: Misfire with error codes P0300,P0302,P01303, P0102, P0748

Have you tried new Spark Plugs? Also after removing the plugs.
Take a paper towel and roll it up so it is like a long thick pencil. Stick that down the hole the spark plus came out of. Just to clean the moisture out. Also blow some compressed air down the hole.
Make sure all the moisture is out. The put the plugs in.
When you wash you car. Be careful if you wash the engine.
Dont let water get in to the plug holes..

SOURCE: Misfire with error codes P0300,P0302,P01303, P0102, P0748

have you checked the wires for holes.

SOURCE: MISFIRE CYLINDER #3 CHECK ENGINE LIGHT COMES ON VEHICLE

Check spark plug wires for corrosion

SOURCE: My 96 honda accord is giving me three different

I would start with a full tune up. If it has never been done then that is the best way to start. Make sure that you gap your plugs. NGK plugs are the best for any and all Honda's. Let us know how it goes.

ZJ Limited

• 17989 Answers
• Posted on Dec 29, 2009

SOURCE: 2002 Saturn SL1 check engine light code P0303

For old models, Saturn/GM also used the same material fiberglass gasket in your model, you almost certainly have a leak from a crumpled, sucked-in gasket as I suffered (and many others). I would say going to Saturn dealership to make repairs is probably not good idea if they are going to put in the same GM intake gasket part. Maybe possible to specify Felpro gasket with whatever shop you go to if you don't do the repair yourself. I would not go too long with your car in that condition as there is localized leaning at your cyl-3, that could cause a burnt exhaust valve there.

The exhaust is extra hot venting out that cylinder. P0303 is misfire at cyl-3. Mine was P0301 (cyl-1). You may get P0507 once in a while when PCM fails to control the fast idle caused by the leak under certain conditions. Most of the time, it is very slow idle caused by 3 cylinders running. You run smoother in cold idle because the IAC opens up to increase idle and end up lowering the manifold vacuum, so the reduced vacuum causes less leaking at the failing intake manifold gasket.

I'd say try cleaning everything with your ignition before replacement; Idle problems could be caused by engine coolant sensor (ECTS). Are you sure it was changed? Did they put on a new wire connector along with it?

Hope helps.