Hey All

My car has been throwing a CEL for a bit and its due to a misfire in three cylinders. This is most evident on a cold start but can be heard sometimes while driving at regular speeds. Went about changing the plugs and battery (battery was on its last leg) thinking it was something minor but to no avail. Any additional signs I should be looking for to diagnose the issue? I am playing with the idea of new ignition coils thinking mine could have gone out but was also considering the timing belt as a source of the problem. Car is a MY05 with about 70k on the clock. Spoon N1 exhaust and test pipe with PRM intake. Nothing crazy done on the motor, regular tune ups and no tracking. Any advice would be greatly appreciated!

 

It's not the timing chain.

 

What are the codes exactly?

Have you checked this out yet? https://www.s2ki.com/s2000/topic/659930-misfire-thread/

 

S2000's have a timing chain, not belt. The chain wouldn't cause a misfire anyway. First of all have the codes pulled and list them. If you are having misfire issues there are a few things you should check. Compression and leakdown test, check valve clearances and adjust as needed, confirm spark from each coil, and in some instances your injectors may need to be flow tested, but I wouldn't count on that one.

 

Awesome thanks for the help guys. I'll try troubleshooting a little more using the stuff from the thread and let you know whats up. Also, the codes were 1 2 and 4 cylinders misfiring.