Chasing a misfire

[05ruster]

Hey guys, let me pick your brains here. 2005 mountaineer 4.6L. I have a nasty misfire cylinder 4. Drives like a slug, shaky on the highway. Showing code p0304. Although I did all new plugs and coils last year, I popped a new one of each into it. No change. Should I move into a new injector at this point? Also showing an O2 code but I doubt it's related. (Prob just need a new sensor)

 

[Fix4Dirt]

o2 can cause misfire. it sends the comp wrong info

Can a Bad O2 Sensor Cause a Misfire? | 1A Auto

Check engine light on? In this case, my 2004 Nissan Titan was running rough and when the light came on, it wasn’t a huge surprise. Was it a bad O2 sensor?

www.1aauto.com

 

[Bookworm370]

Are you getting a too rich or too lean from the O2 sensor? The ECM will adjust the fuel injector open times (PWM) if it determines that the engine is running too lean. If too rich, it will reduce the fuel mixture. But, this can also be caused by a MAP sensor, some intake leak or just something lose or died in cylinder 4 .

 

[94Eddie]

Hey guys, let me pick your brains here. 2005 mountaineer 4.6L. I have a nasty misfire cylinder 4. Drives like a slug, shaky on the highway. Showing code p0304. Although I did all new plugs and coils last year, I popped a new one of each into it. No change. Should I move into a new injector at this point? Also showing an O2 code but I doubt it's related. (Prob just need a new sensor)

Did you replace the coils with Ford OEM parts?

 

[Bazz270]

Hey guys, let me pick your brains here. 2005 mountaineer 4.6L. I have a nasty misfire cylinder 4. Drives like a slug, shaky on the highway. Showing code p0304. Although I did all new plugs and coils last year, I popped a new one of each into it. No change. Should I move into a new injector at this point? Also showing an O2 code but I doubt it's related. (Prob just need a new sensor)

Probably ....you will need a replacement catalytic converter that clogged because of the keep running with misfires.