Changed the coil but still runs rough under load however pretty smooth at idle. Thinking spark plug or injector. Engine light flashes and cylinder 8 misfire code only when pushing the engine hard. Anyone done an injector ?

 

That's a bad misfire, yes.

Sounds likely a coil or its wiring / connector but I guess plug would be on the list. Dunno if it could be injector, sorry.

I suppose the PCM driver circuitry could be bad but the PCM is very very robust so probably not.

I don't know if the PCM is 100% always right about the cyl #. Supposing it isn't I also don't know whether 7 or 6 would be next to try. Anyone?

 

You can try swapping the "new" coil to another cylinder and see if the fault moves with coil-pack. What brand coil did you choose for a replacement? Hopefully not a no-name coil from that famous auction site, manufactured by the Sum Ting Wong Parts Manufactory #37...

A look at the condition of the spark plug in #8 would also be in order; if there has been a misfire for a while, the plug may be fouled. How long have the plugs been installed in the engine?

 

Yes I tried swapping coil to different cylinder and it came back cylinder 8. Ordered some Bosch platinums since they’re well overdue and 7 more coils just to tune everything. Brand im using is called spectra premium. I should know what’s going on once I remove the spark plug this weekend. Thanks for the quick replies