Q: Service Code P0300

[AznJohn22]

I have a service code P0300 for my 2008 Nissan Rogue. I bought it into my garage guy instead of a Nissan dealership. He said not to worry about it and cleared the code. The Rogue has 31,000 miles and i didn't bring it in for the 30,000 Service Maintenance. Should I bring it into a dealership to make sure everything is fine? Thanks.

[fstrchld15]

always better too be safe then sorry.

[kerrton]

That code appears to indicate a cylinder misfire which is definately not something I would recommend ignoring. Was the car running rough when you brought it to the shop, how does it run now?

When you took the car to your mechanic, I'm assuming the check engine light was on? Since your mechanic cleared the code, has the check engine light come on again?

I would recommend taking it to a Nissan service center for diagnosis, your engine is still under warranty so if there is problem it will be covered. Please get back to us with some more details...

[AznJohn22]

The service engine light has not come on since. It has been cold in NYC and have not been warming my car before driving. Might be the reason.

My feeling is if I bring to dealership without a specific problem, they are going to rob me blind.

[kerrton]

Your powertrain is under warranty, check engine codes or drivability issues with the engine will be covered free of charge. If you notice any problem in the future I wouldn't hesitate to take it to the dealer for free diagnosis and repair.

[ralican2130]

P0300 -IS A RANDOM MISFIRE which means your 1,2,3 or 4 cyl is misfiring.. P0300 is hard to troubleshoot because it's random, which means it could be your sparkplug,coil,coil boots,coil harness or the whole module and sometimes it comes to your fuel system and O2 sensor.... i would suggest go back to your "garage mechanic" and kick his a**

[AznJohn22]

I've driven the car a few times since and the service light has not come on.

[kerrton]

I think what ralican2130 was saying is that your mechanic should not have let you leave without determining the cause of this serious issue or he should have explained more fully what caused the code - a cylinder misfire is not something to just shrug off, clear the code and let the owner be on their merry way thinking their vehicle is running great.

Or perhaps we don't know all the details here, he may have done something to cause the misfire (ex. spark plug wire was disconnected, etc.) and so he was content to reconnect the wire, clear the code and move on. I would tend to guess something like this occurred which is why he told you not to worry about it. But this is all speculation. Bottom line, if you notice any issues take it to a Nissan dealership for warranty work.

[ralican2130]

Aznjohn, it doesn't mean that the light is not coming out your good.. you could actually feel it while you are idling that you cylinder is misfiring or even at WOT, there's a bunch of test that your mechanic should do to detect a misfire.. kerrton is right, you already have a code! why would you erase it, you supposed to fix it rather than chasing a ghost .

[SnookieTownshend]

I'd be concerned if my mechanic told me not to worry about something without telling me why I didn't need to worry about it.

It could be anything in the entire fuel system. A "Random Misfire" code on my Saturn was what alerted me (and my mechanic) to a problem with the throttle body (clogged) and throttle switch. An easy fix since they caught it early.