2012 Yaris SE Firing Order - Troubleshooting P0304 Code

[SoCalSTEVE]

Troubleshooting a P0304 code and wanted to verify the firing order is 1,3,4,2 with 1 being on the passenger side.

Thanks

[ex-x-fire]

Firing order & cylinder layout are two different things. #1 is near the belt & pulleys, #4 is at the opposite end.

[thebarber]

agreed, cyl 4 is on the transmission side, cyl 1 on the passenger/belt side.

best thing to do is swap the coil pack from 4-3 and the injectors from 4-2. see if the misfire moves or stays. they you'll know whether the issue is the spark plug, coil pack, or injector.

[SoCalSTEVE]

Thanks for the clarification and info!

[SoCalSTEVE]

Looks like the code cleared for a bit, but now it’s back. Going to swap the coil pack first and see what it does.

[SoCalSTEVE]

Just an update swapped coils and spark plugs and turned out to be a plug causing the misfire.