Hi had a CEL recently, took the car to Honda who pulled up the codes:

P0301 7 - 1 P1399 ____ Cylinder 1 Misfire Detected
P0302 7 - 2 P1399 ____ Cylinder 2 Misfire Detected
P0303 7 - 3 P1399 ____ Cylinder 3 Misfire Detected
P0304 7 - 4 P1399 ____ Cylinder 4 Misfire Detected

This happened 3 months ago and all the plugs were changed. The guy at honda does not know what to do, he has mentioned injectors, wiring looms etc. Ive had a reset but I know its a qustion of time before it happens again. Any help will be appreciated.

Thanks

 

Mine was doing "misfire" codes without anything else. Turned out to be injectors.

 

Random Misfires can be caused by a number of things. It can at times send you on a wild goose chase. Are you experiencing any of the following symptoms:

1. Rough idle.
2. A pulsating exhaust - are the exhaust gases flowing smoothly out of the exhaust?
3. Have you noticed any loss of power at low or high revs?
4. Has the car ever been mechanically over reved?

Fouled plugs can generate the codes but other things to consider are; coil packs, fuel injectors and ECU. In severe cases bent valves also produce misfire codes.