P0303 Cylinder 3 Misfire Detected

[Hi Fi]

I would like to know where the Cylinder 3 is.
And how to check for this problem.
Anyone have a picture of the order of the plug numbers?
Thank-You.

[ohlord]

of the car,on your left(passenger side)front to back is bank 1 cylinder 1 is the first,then 2 and 3.....right side (drivers side)front to back 4,5,6.
So Cylinder 3 is the furthest back 2 plugs on the passenger side.Check that both plug wires are firmly popped onto the plugs.Makes it easier if you remove the air box and the tube all the way back to the clamp after the mass air sensor.
Report the results.
ohlord

[Check Codes]

Hey, Hi-Fi.

Ohlord has you on the right track. In addition to removing the intake plumbing you gain a bit of extra clearance back there if you unscrew the coil (T15? torx) and gently move it out of the way; an old hanger wire will help to hold it aside. Be careful not to pull on the wires themselves at any time as they are easily damaged and quite expensive. And be sure to put the wires back on the right plug, top wire to front plug.

Last thought: plugs are a 100,000 mile item so if you are getting close you may just want to order them and replace them. Plugs nearing their end of life are fairly common causes of misfires.

Take care and enjoy the ride,
Greg

[Raptor102]

I tried to find an answer to this but haven't seen anything yet so sorry if this is a duplicate. I have a check engine light and it pops code P0303 on my 2000 E320. It runs very rough at startup as it's idling and I have almost no accelleration. As I have 76K on the car I figured I'd change all the plugs at the same time while I was at it. I did change all of the plugs and definitely reseated all of the boots well. However I still have the exact same issues as far as the symtoms above. Am I looking at possible bad wires or the coil? Any ideas on how to verify if one or the other is bad? Thanks

[Check Codes]

Originally Posted by Raptor102

I tried to find an answer to this but haven't seen anything yet so sorry if this is a duplicate. I have a check engine light and it pops code P0303 on my 2000 E320. It runs very rough at startup as it's idling and I have almost no accelleration. As I have 76K on the car I figured I'd change all the plugs at the same time while I was at it. I did change all of the plugs and definitely reseated all of the boots well. However I still have the exact same issues as far as the symtoms above. Am I looking at possible bad wires or the coil? Any ideas on how to verify if one or the other is bad? Thanks

Hey, Raptor.

Since the coils are interchangeable the easiest thing to do is swap #3 with one of the others (plug wires and all). If the problem moves then it's either the coil or the wires, the wires are suspect enough you could probably just replace them first. They're stunningly expensive (about $10 to $25 each depending on if you buy a complete set and where you buy them) so you might want to isolate it further, but that means pulling them out of the coils, which could damage good wires. Personally if you swap it and the misfire code moves from where it was to the new cylinder I would probably buy two wires and a coil and call it a day; that way you're covered.

If after swapping coils the misfire stays at #3 you have other issues, but try the swap first and see where that leads you.

Take care and enjoy the ride,
Greg

[Hi Fi]

The screw of the coil for cylinder number 3 was a bit too tight. I unslacked the screw for this coil and my code went away. Thanks for all the help.