I have a 2005 Legacy 2.5i non-turbo. Starting yesterday the engine started hesitating a tiny bit on acceleration while my wife had the car. That evening she noticed the engine light went on and the cruise control light started flashing.
I went to a parts store today and they pulled a code - P0303. Misfire in cylinder 3. After hearing the cars issues, the parts person said most likely plugs, plug wires, or ignition coil issues.
The code is off now, but the car continues to hesitate when under load - more noticeable when accelerating in 1st gear. Idle is fine. Starting seems ok too.
I bought the car 6 months ago from a family member. It has 150,000 km. The head was redone (with new plugs) around 90,000 km - so 60,000 km ago. Not sure if plug wires were replaced but they look to be in ok condition.
I removed the #3 plug today. I've attached a few photos if someone could give their opinion.
I'm thinking to buy new NGK OEM platinum plugs at around $9.99 CDN each. If that doesn't solve the issue perhaps I should replace the plug wires?
A diagnostic seems to cost a few hundred bucks, so I thought why not replace the plugs before going that route?
Thanks for any / all advice!