Hi guys, hope everyone is safe and healthy out there.
Recently my car has developped a misfire issue. I am keep getting this P0302 code, which I have checked online its the cylinder 2 random misfire. I have changed spark plugs (4 of them) and I swapped the coil pack from different cylinders to cylinder 2. And still has the code keep coming back.

My car is an 2006 with 50K-ish miles, only has k&n intake with q300 exhaust, otherwise stock car.



Anything would help, Thanks!!!

 

Valve clearance.

Inspect the valve clearance and do a valve adjustment before they get burnt. I can almost guarantee the exhaust valves will be tight in all cylinders and even more so in Cyl #2.

 

I see,
how many miles usually a valve adjustment is needed?

 

There are lots of threads on misfire issues (not always easy to diagnose).

The top sticky thread in this forum (link) warns you about checking valve clearances on 06-09 models.

 

I've seen tight exhaust valves cause a misfire on multiple vehicles, not just S2000's.

With the 06-09 S2000, it's recommend getting the valves adjusted every 50k miles. The DWB cars run much leaner aka hotter which cause the valves to tighten up much quicker over time.

Just do yourself a favour, remove the valve cover and inspect the clearance, it doesn't cost anything and it's better than throwing parts at the car.

 

gotcha!
I will go ahead to take a look there.
Thanks so much!!!

 

Roger,
Thanks so much for the info!!!