Hey Guys!!
I need to draw on your knowledge...
I had a P0300 code yesterday, and the engine was idleing pretty badly. I have a dual exhaust and one tip had a smooth constant flow the other one was choppy and sputtering.

I replaced the spark plugs today...they actually looked okay (75,000km on engine) One had a little bit of oil on it...

I cleared the ECU and did the idle air volume relearn.
The car started up a little rough, but seemed okay on the road.
Should I be worried or check anything else??

 

I recently had an issue and that code showed up. According to my research, P0300 is caused by one or more of the following issues;
* Faulty spark plugs or wires
* Faulty coil (pack)
* Faulty oxygen sensor(s)
* Faulty fuel injector(s)
* Burned exhaust valve
* Faulty catalytic converter(s)
* Stuck/blocked EGR valve / passages
* Faulty camshaft position sensor
* Defective computer

In my case, the timing valve was clogged by Engine Oil Additive. Have you recently used Engine Restorer or some sort of additive?

 

Hi Kawasaki, I found that info too. Just not sure how to check them all. I haven't used any additives. I just took it for a spin, and the idle still seems off. I think I'll have to take it to a shop.

 

I also had this problem and it turned out to be 2 blown coils. My G had the exact same symptoms as yours also. It had been raining a lot the previous 2 weeks before this happened and moisture somehow got into my ignition system and blew 2 coils. Unfortunately it can be many things but your symptoms lead me to believe it could be the one or more of your coils or something with your ignition system. Hope this helps.

 

I have 4 extra coils I'm not using. I'm selling them cheap. PM if you're interested.
Not saying thats your issue, but its very very possible. Not likely to be your plugs.