hey guys so been having an issue with my 03 350z and i’m just lost with what it could be so anything will help. Basically on start up, the car drives perfectly fine, no issues and no lights on the dash. once i drive for about like 20+ minutes and go into neutral, the rpm’s become unstable, and this doesn’t happen all the time sometimes i’ll drive and it’ll be fine. so the rpm’s start to drop and will drop to the point where the car shakes and turns off for like a split second, but picks itself back up again (sometimes it will turn off completely and i will have to turn it back on). Once this happens the car enters limp mode (i think), but there’s no lights on the dash and the rpm’s kick up to about 1k in neutral and just remains there and when i drive or rev, im not able to pass 2500rpm, and if i try the car will start jerking/shaking back and forth. On top of this the car starts making a smell from the exhaust as if oil or fuel is burning not too sure which. If i turn the car off for like a minute then it’ll be back to normal and i can drive it fine.

anyway, played around with some things checked the condition of the MAF sensor and it looked basically brand new so didn’t think it needed a clean. Ended up taking it to my mechanic who scanned it and got a code for the knock sensor (po303), and he cleaned my throttle body as well. He cleared the code, drove it for a couple days and it was fine so thought the issue was fixed but it ended up happening again after a few days. Went back to my mechanic for another scan, knock sensor popped up again but it was a different code (po327) and he thinks the cause of all this is the knock sensor being faulty or wires have gone bad due to heat.

Any suggestions on what the issue could be? I thought it could be related to the MAF sensor or throttle body causing the car to have a low idle, or even something with the fuel pump or injectors. Just weird how it doesn’t happen all the time and when it does, only after about 20 minutes of driving. It could just be the knock sensor behind all this, i don’t know too much about them so that’s why im not entirely sure it’s the cause.

and if it helps the cars pretty stock, i bought it about 3 months ago, just had a CAI on it and i recently installed an exhaust on it.