Greg8444
Member
2012 5.7L with 117k miles. Replaced the plugs only, no coils, last fall, around 15k miles ago.
Recently it's started throwing a P0303 (cylinder 3 misfire). It doesn't throw this code while driving "normally" but it will happen when going uphill or under harder-than-normal acceleration (I'm not a leadfoot unless I'm in AZ in a rental Challenger). It's ALWAYS the #3 cylinder.
Assuming it was the coil pack, I replaced that but it's still doing it. I supposed it's possible I got a bad coil pack. I suppose it's also possible that one of the plugs went bad. But both those scenarios seem unlikely.
I do have AlfaOBD, if there are any better diagnostic tools than just the standard app that came with the OBD dongle I bought.
I've heard something like this could be an early indication of cam failure (I really hope that's not the case). The fact that it's always the #3 cylinder makes me thing it wouldn't be a cam/crank sensor.
Any thoughts on what else might be going on? I have an appt at my local shop on Monday, but I'd like to have a better clue before going in there.
Thanks in advance.
Recently it's started throwing a P0303 (cylinder 3 misfire). It doesn't throw this code while driving "normally" but it will happen when going uphill or under harder-than-normal acceleration (I'm not a leadfoot unless I'm in AZ in a rental Challenger). It's ALWAYS the #3 cylinder.
Assuming it was the coil pack, I replaced that but it's still doing it. I supposed it's possible I got a bad coil pack. I suppose it's also possible that one of the plugs went bad. But both those scenarios seem unlikely.
I do have AlfaOBD, if there are any better diagnostic tools than just the standard app that came with the OBD dongle I bought.
I've heard something like this could be an early indication of cam failure (I really hope that's not the case). The fact that it's always the #3 cylinder makes me thing it wouldn't be a cam/crank sensor.
Any thoughts on what else might be going on? I have an appt at my local shop on Monday, but I'd like to have a better clue before going in there.
Thanks in advance.