Anybody have any idea wtf this might be?

Memphis370Z

Sorry about your trouble, especially so soon after buying your Z.

When the guy at AutoZone did a scan, did you get the actual code that he read? If so, what was it? Also, what was the code that the dealership got when they scanned your Z? I believe the code for a #5 cylinder misfire is P0305. Also, do you have any mods?

I'm sure others will chime in, but just wondering, specifically, what code (or codes) your getting.

In the meantime, here's a thread regarding a #5 cylinder misfiring - Took to Dealership - Royal Purple.

GunWorxx

I don't remember the code Auto zone had, but the dealership said they got like a P0300 which is a "random misfire" code. The only mechanical mod is Apexi exhaust.

Memphis370Z

Odd, since P0300 denotes random misfires for more than one cylinder. I believe that the last digit denotes a specific cylinder misfire, so P0305 would refer to a problem with the #5 cylinder. Maybe I'm just splitting hairs, but it's interesting that the guy at AutoZone mentioned the #5 cylinder specifically.

Anyway, if you want to check on your own, I would start by looking for vacuum leaks and, if you're so inclined, pull the plugs and check them for proper gap and/or to determine if they're fouled. Otherwise, let the dealer handle it under warranty.

Either way, good luck and let us know what you find out.