Over the weekend while driving up 101 to go to dinner my car started shuddering and shaking pretty violently when I accelerated while merging from 85 north to 101 north, and then the check engine light started blinking. I limped the car an exit or two and got off the freeway, where I pulled over and plugged in the diag tool and it gave me error code P0304 -- cylinder 4 misfiring.

Since I bought Subaru's extended warranty, I'm going to call Subaru about it, but there's a couple things I'm wondering about:

1. I put a Greddy TI-C CBE on the car a few months ago, should I put the stock back on before taking it in?

2. When I bought the car from Stevens Creek Subaru it came with an aftermarket gauge cluster already installed.

I ask about these things because I'm worried that whoever I take it to for warranty work will turn me away because the car has equipment that is not "manufacturer approved" per the exception clauses in the extended service agreement.

Thoughts?

Also, wtf, cylinder 4 misfiring. I haven't missed any of the scheduled service for the car, I don't beat on it -- in fact, I baby my car.

 

Exhaust shouldn't mean anything.

What guage cluster are you talking about?

Cylinder misfire could be caused by more than just beating and missing service. Bring it on in.

 

I don't remember the manufacturer (the car is at my friend's shop right now), but it's the boost PSI, fuel pressure and voltage, with red lighting and the case for the gauges is kind of rounded over each gauge. All I know is that it was there when I bought it. I'm pretty sure Chris remembers, he helped me fix it (hose came off) the same day I brought the car home.