I have been having CEL P0303 - Misfire Cylinder 3
I've replaced fuel filter, plugs, plug wire, dist cap, rotor and injector all OEM from stealership...also put in a brand new 02 sensors, with all these new parts I still keep getting the same code can anyone give me any ideas as to what could be causing this?

Timing is fine, does not sounds like any misfire in the engine. Steady cruising from 2K - 3K CEL would flash. poor gas mileage.

Just recently cleaned the EGR chamber replaced and slapped in a new EGR gasket.

btw, car is stock 97 Civic HX with d16y5

Someone who knows something, please help me out!


Modified by Datu's Tribe at 12:02 PM 9/9/2008

 

ttt anyone?

 

are the new plugs gapped correctly? check the compression you have have a dead hole.

 

plugs are pre-gapped from dealership...will check the compression.

thanks! I really appreciated it

 

Okay...I've double check the gap and all seems fine and I did the compression test:

1st cylinder: 190
2nd cylinder: 160
3rd cylinder: 180
4th cylinder: 190

there was no bubble coming out from the coolant during the test. It seems internals are fine...please help me out! MISFIRE is PITA!

 

bump

 

Did you use the factory recomended plugs, in my experience honda engines don't like the skinny tipped platinum plugs. I swapped mine and got missfires till i put oem recomeded types in.
If it's only giving a missfire code on one cyl, it indicates the high voltage side of the distributor/plug wires/plugs/cap, or you have a problem inside that cylinder. possibly leaking water into that cyl or a bad valve seat or ajustment maybe.

 

Plugs are all OEM from dealership, they are the same plugs I've been using since I got the car 8 years ago. so I don't think its the plug. Im going to look into adjustment and valve.

Thanks for the info.