So i put my 2003 nissan 350z under the scanner today after dealing with the stealership bsing me around for the past 4 months and i ended up with a p0300 code i took out the sparkplugs and replaced them car had the same problem, i took out the fuel injectors and they look brand new replaced all the o ring and replaced the intake manifold gaskets and car still had the same problem, so i went back to the scanner to do a little further diagnosing and i looked at the o2 sensor and the bank 1 sensor before the cat is fluctuating anywhere from 300 to 800 rapidly and the same goes for the bank 1 sensor behind the cat but from 100 to 700 but the bank 2 sensor both before and behind the cat are staying steadily at 280 i removed the o2 sensor before the cat on the bank 1 and started it up but the car kept misfiring any help would be much appreciated the car has been sitting in the shop and costing me daily help please!!!!!

 

Chk your ignition coils also

 

How so I just wrapped them in electrical tape

 

How so? Get a good scanner and see which cylinder is misfiring--then replace that ignition coil with a new one. I don't understand wrap them?

 

I wrapped them In electrical tape so it doesn't allow the spark to escape and it's a p0300 multiple cylinder misfire it would be more then one if that's the case and I highly doubt more then one coil pack failed at a time

 

Usually not more than 1 at a time but there always a possibility