Nissan 370Z Forum - View Single Post - P0300, Rough Idle Out of the Blue - Anything other than spark plugs before road trip?

JSON · 01-23-2021, 05:25 PM

I was getting ready to go back home with my 850 mile drive and started up the car this morning. I noticed heavy fuel smell immediately. After driving a few miles, it felt like the car had more vibration, even during idle. Idle RPM initially seemed fine at around 700 RPM, but I could feel more vibration and hear the "subaru exhaust" noise. I remember this happening when one of my coil packs went on my old Acura.

After a couple of more miles, the Service Engine Soon light started blinking. I checked the code at Autozone and got the P0300 random misfire. Now the idle is at 1000 RPM and the noise/vibration is worse. I bought 6 new spark plugs from the dealer and am about to do that and clean the throttle body a bit while I'm at it.

I got 95k miles, catback exhaust (stock cats), K&N air filter, and it has been running fine until this morning. I changed out the leaky fuel dampener maybe 10k miles ago. My exhaust might be leaking a little, but this issue came out of nowhere and have had the exhaust/air filter on for 20k+ miles, so I feel like that isn't the issue. It was kind of cold this morning (40ish), but it was in the 30s the week before and didn't have any of these issues. I thought maybe I got bad fuel, so I topped off from another gas station with about 5 more gallons.

Anything else I should try?

01-23-2021, 05:25 PM	#1 (permalink)
JSON Base Member Join Date: Jul 2015 Location: Houston Posts: 50 Drives: 09 AW 370Z Sport 6MT Rep Power: 10	P0300, Rough Idle Out of the Blue - Anything other than spark plugs before road trip? I was getting ready to go back home with my 850 mile drive and started up the car this morning. I noticed heavy fuel smell immediately. After driving a few miles, it felt like the car had more vibration, even during idle. Idle RPM initially seemed fine at around 700 RPM, but I could feel more vibration and hear the "subaru exhaust" noise. I remember this happening when one of my coil packs went on my old Acura. After a couple of more miles, the Service Engine Soon light started blinking. I checked the code at Autozone and got the P0300 random misfire. Now the idle is at 1000 RPM and the noise/vibration is worse. I bought 6 new spark plugs from the dealer and am about to do that and clean the throttle body a bit while I'm at it. I got 95k miles, catback exhaust (stock cats), K&N air filter, and it has been running fine until this morning. I changed out the leaky fuel dampener maybe 10k miles ago. My exhaust might be leaking a little, but this issue came out of nowhere and have had the exhaust/air filter on for 20k+ miles, so I feel like that isn't the issue. It was kind of cold this morning (40ish), but it was in the 30s the week before and didn't have any of these issues. I thought maybe I got bad fuel, so I topped off from another gas station with about 5 more gallons. Anything else I should try?