"Limp Mode" & service engine light
 

Hi Z peeps,
I have an '09 Nismo and hit this "Limp Mode" people been talking about. Also my service engine light has come on. This all started right after I replaced the original battery. Right after I did that the Service Engine Light came on and will flash from time to time. Driving it to the shop is when I hit that Limp Mode at 3500 rpms (I just got gas (93 octan) before this too), the guy ran the engine code p0300. It's not the O2 sensor..The guy said its sounds like a misfire in one of the cylinders and it idles kind of rough, he spent about 2 hours going all the basic stuff and couldn't figure it out which is weird cause the car only has 36,000 miles on it. so before him pulling the engine apart I wanted to look through these threads and but couldn't really find a good answer for these problems cause Z's love jerking us around with how glitchy they can be but if anyone could give some knowledge on these headaches or had a similar problem and they fixed it, It'd be much appreciated. Thanks!

Also could the Limp Mode be cause by a rare occurrence of getting bad gas from the gas station? Again I always use premium 93.

This should help http://www.the370z.com/engine-drivet...whats-fix.html

I would check to ensure you didn't get anything lose (vacuum hose, elect. connectors) if it happened immediately after the battery replacement.

maybe disconnect/reconnect the battery again and see if the condition goes away.

Have him clear the code and continue about your day. If it comes back then start fishing for solutions. It could just be a gremlin.

I'd try jwick's clear-the-DTC-and-see-if-it-happens-again first. If it comes back, I'd try nis350's suggestions. If it still comes back, take to an expert.

a bloke on this forum had random limp mode after replacing his battery. the fault ended up being loose battery terminal clamps. so check the simple and the silly too ;) goodluck!

Still problems
 

Well after a month now I still don't have the car back! The first shop I went to he found the 02 sensor was broken off cause it wasn't put on right from the factory he sent me the pics attached...he may have found out what was causing it but wants a second opinion before doing the work it's been so long I can't even remember what he said...but now it's at the Dealer and they can't even find out what the hell is wrong with it...they said the cat converter was bad and replaced that (under warranty thank god) and it's still putting out a misfire code...anyone ever go through these problems yet?Attachment 99270