hesitation worse when A/C on

[M_3_X]

Thanks Jeff! I will text you.

fastbub - Thanks for the suggestion. I have no experience with burnt valves. If that's the problem, would the car run as if nothing's wrong with new plugs? Any other symptoms of burnt valves?

Thanks, Cory

Depending on how bad they are, yes. It could be only one valve.
I would run a compression test too. A burnt exhaust valve would throw compression down dramatically.

[Seawolf]

All of those plugs look like they are overheating, assuming you have the correct spark plugs I'd suspect a weak fuel mixture. Maybe marginal fuel pressure or bad/blocked injectors.

An air leak could cause similar plug overheating but you would have a ton of other symptoms so I doubt this is the case here.

It also looks like there are deposits on the plugs, maybe worn valve guides or seals allowing enough oil to foul the plugs, once contaminants bake onto the plugs they can't self clean and will overheat.

A fuel pressure and compression test will eliminate some of the possibles. Though a bad (or wrongly set) TPS, worn AFM carbon track or poor C191 connections are other candidates.

[cory58]

Thanks for the responses! Awesome info. Plugs are correct. Cap and rotor are new. I will start with the compression and fuel pressure, and then report back.

Cory

[Seawolf]

Just one other thing.....I looked again at your list of service parts since that is when the problem started, the only thing I can see there that would likely cause a problem is if the fuel filter was installed backwards...might be worth a quick check.