PilotSi

02 Honda S2000 w/ 45k on the dial.

I downshifted to 4th from 6th on the highway Sunday, laid into the gas, and the car started to misfire. Ran fine before this...

Pulled the CEL.

1,3,4 were misfiring.

Reset.

4 was misfiring

Reset

1,2,4 misfiring.

I borrowed my friend's coilpacks and replaced them one at a time. Didn't matter - it still misfired. Suggestions? It's misfiring bad enough that it's popping in the exhaust loudly. Kind of like an RX7

Reds2kracer

Have u read the FAQ yet?

https://www.s2ki.com/forums/index.php?showtopic=659930

Mine never came back after changing the injectors, cleaning the IAC valve, and changing spark plugs. You might even need a valve adjustment and or compression test.

PilotSi

Yep - I read the FAQ...I have plugs that are 3 months old, and Valves just relashed at the same time. I'll try cleaning the IAC.

Thanks!

Mister Jew

how many miles?
i had a random misfire it turned out my injectors werent evenly distributing fuel. i got them cleaned and tested and no more cel

Tech7427

so from this 6th to 4th shift, was it really fast shift? kinda like, maybe bent a valve or 2?

just an honest question.

is it missing at idle/load etc?

The Gent

Popping on idle leads me to believe it's the injectors. Had to replace mine after doing all the steps.

https://www.s2ki.com/forums/index.php?showt...&#entry15658384

03-toda-s2000

sounds like you need to get a compression leakdown test and check the valves. Just got done fixing this problem with my S had almost no compression at all in cylinder 3 and it pulled codes for a bunch of random misfires too. Hope your valves aren't bent!