troutman56

So I've been chasing problems on the gs300 (2jz) and initially had an O2 sensor code and an ocv code as well as the codes above. I replaced the o2 sensor and cleaned the ocv filter which was completely clogged. I also replaced all plugs and the oil control valve itself. None of this has changed any symptoms. The only codes I get now are the ones in the title so apparently those others needed replacing anyhow? Now, the next thing I was thinking was coil packs, but the cylinder numbers are not related. The only thing I can think of is the each of the misfiring cylinders are the ones where the boot sits on the plug, not the pack itself. Is it possible my boots all went bad at the same time? Seems unlikely but that's the only thing that seems to make sense. Id hate to keep throwing parts at this thing but it may be time to go get raped at the dealer soon. Any advice?

Mr Jokster

iTrader: (8)

A timing issue or maybe a vacuum leak listen for a hissing sound.

troutman56

Didn't hear any hissing but once the engine got to operating temp I could hear the throttle body chattering as if someone was using it to send morse code. Timing belt was done recently and it's possible it could have jumped timing but we put almost 2k on it since that change.

wbmx1981

Replace your ignition coils and this should fix your misfire. The ignition coil boot goes over a plug then a wire from the coil goes to another plug so they are all connected (One coil per two plugs). New plugs can put stress on old ignition coils causing them to intermittently glitch or fail.

I had new plugs, new wires, and 16 year old ignition coils. My car ran smooth, but when I floored it my car would flutter or hesitate, followed by a misfire. After getting the 0301 code and few days later I got the o2 sensor code 0430 bank2. I replaced all three coils and no more codes and no more hesitations/fluttering/misfire. Good luck.