2003 G35 with plenum spacer and ECU reflash. Check engine light came on a few days ago, went to AutoZone today at lunch, code is "random multiple cylinder misfire". I searched on-line and found the possible symtopms:

* 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

Also saw: Random misfires that jump around from one cylinder to another (read: P030x codes) also will set a P0300 code. The underlying cause is often a lean fuel condition, which may be due to a vacuum leak in the intake manifold or unmetered air getting past the airflow sensor, or an EGR valve that is stuck open.

The two symptoms that make me nervous are defective computer and
vacuum leak in manifold, because of my mods. I don't really want to take it
to the dealer, again because of the mods.

I didn't notice any change in performance and after AutoZone checked the code, it disappeared. What do you guys think? Take it to the dealer or keep
driving and see if it comes back?

 

what code # came up,need a little more info.

 

I think he said 300

 

It Happend To Me, Go To The Dealer Its 90% Just A Sensor. MY CHECK ENGINE LIGHT CAME ON AND IT SOUNDED LIKE A MISFIRE. GO TO THE DEALER ASAP, THEY WILL REPLACE A SENSOR FOR YOU.

 

Ok Sounds Very Good Thank You For The Capitol Letters