i just bought a 2000 GSR, i know it needs an O2 sensor, but last night i put a new AEM dry air filter on it and filled the tank with WAWA 92 octane. i probably shouldn't have put no name fuel in it, but it was late and i didn't really have a choice. my problem is, on my way to work this morning i came to a light just down from my work and my check enging started to blink and i noticed it was missing on a cylinder. i drove the 2 miles to my work and shut it down. any ideas? it had a real dirty K&N filter on it which i replaced with above mentioned. so do you think the mixture of bad o2 sensor, new air filter and possibly crap tank of gas could lead to a fouled plug?

 

Replace the bad O2 sensor, clear the codes and then see if the missfire CEL reoccurs.

 

its possible, just have it cleared and see if it comes back.

o2 sensors are pretty important.

 

well i found out the problem. i do have an o2 sensor problem, but the real problem, after i checked everything else, i did a compression test... i have 230psi in cylinders 2-3-4. cylinder 1 has 0psi. i took a closer look at the intake tube and noticed it was the upper part of of a non-V2 AEM cold air... cut... well who ever cut it never bothered to clean it out so when i changed air filters all the new fresh air with considerably increased velosity, sucked aluminum debris into my intake runners clogging up behind one of the valves on #1, and now it can't close properly. so now i have to pull the head, replace all the top end gaskets and clean the valves. i also need to change the timing belt and water pump. i'll have it fixed probably in a week or so. i work two jobs so i have limited time, but thanks for a little help from my friends i think i'll be ok. thanks for all your help. now i'll be able to install that skunk2 intake mani. and my new AEM cam gears.