98 Mitsubishi Eclipse Spyder GS-T

[Ssemple]

Just bought this car from the original owner with 40,000 MI.
All maintenance has been done with this car, from motor mounts to timing belt and much more. If I really step on the gas it will misfire sometimes at higher RPMs and the check engine light will come on. I'm getting a code p0301. Most common solution is replaced spark plug wires and spark plugs. This had been done about 4 years ago, with only 3,000 mi since. Any idea what other issues that might cause this.

 

[Ludachris]

Not running low octane are you? Is this a turbo car or n/a? Check the simple stuff first; pull the spark plug on cylinder 1, see if it's fouled and check the gap. Look at your injector wiring on that cylinder. Check all the wiring to the coil. Try switching a couple spark plug wires to see if you get the misfire on a different cylinder, which would obviously narrow it down to a bad wire.

Could possibly be the injector. Could be the coil pack. Try the simple stuff first and rule things out.

 

[Ssemple]

Using high octane. Worried about taking this to a mechanic and not getting a good diagnosis, the first round of money spent.

 

[pauleyman]

Just bought this car from the original owner with 40,000 MI.
All maintenance has been done with this car, from motor mounts to timing belt and much more. If I really step on the gas it will misfire sometimes at higher RPMs and the check engine light will come on. I'm getting a code p0301. Most common solution is replaced spark plug wires and spark plugs. This had been done about 4 years ago, with only 3,000 mi since. Any idea what other issues that might cause this.

I'd still suspect wires especially at the coil side. If it does it at idle you might spot it in a pitch dark location and you can see it arc. Pull the wires off and inspect the boots. Look VERY closely for small white dots. If you find one it's a burn hole through the boot. Cracked or corroded coil tower also. Particularly if the coil is original (and likely is).
If it does it under boost only that's also a sign. High load, ignition takes path of least resistance. Happened to me decades ago as a new DSMer. Thought for sure I'd blown something up.