2004 G35 sedan, 127,000 miles. I have a warning light, not CEL. My scan tool gives me P0327, knock sensor.

I recently purchased the car from my neighbor. He's always run 87 octane. He had the code once a few years back, but I'm getting it if I drive more than an hour. I can clear it, but it comes back. When it codes, I have no issues regarding power, idle, MPG. It does not seem to be any different.

Could 87 octane be an issue? Will a higher octane correct issue? Or, once it codes is the sensor likely bad? Am I hurting the engine? I imagine this is a costly fix. I've changed the knock sensors on my GM truck, but this seems too labor intensive for me.

Any advice is welcome. Thanks.

 

No you're not hurting the engine but it also won't advance timing via the cam actuators so you're missing a LOT of potential power when you step on the throttle. Usually the code is being thrown because of the sub harness failing, there's a few threads you can read about folks who have managed some kind of trickery and swapped the harness with coat hangers and various long-reach implements. Personally I would just tear off the upper/lower/collector intake manifold and replace the entire sensor with a new Nissan one along with the sub harness, especially if you have 100k or more miles on the vehicle since that sensor, along with all the others, only lasts so long before failure.

 

No!

I'm on my third Infiniti and only use 87 octane since December 2005

Telcoman

 

Please help. 2004 g35 SDN auto. Had camshaft position sensor (bank 1)repaired 5 months ago and did not repair code PO327 knock Sensor 1. Was getting ready to repair PO327 and Service Engine Soon light went off so I didn't repair. Now it is Oct and car again has the two same codes PO34O and PO327. Car loses power, hesitation starting and bad gas mileage. Help please.

 

P0327 is most commonly caused by the knock sensor sub harness however it's a bit of a chore to pull the upper/lower/collector intake manifolds so most just replace the sub harness AND the actual sensor. Use only OEM parts or you'll likely be taking it off a second time because aftermarket sensors are trash. If OEM is out of your budget then at least go with a name brand like Hitachi (who is an OEM supplier for some sensors on this engine) to minimize chances of a second repair.

P0340 is the bank 1 cam sensor which is a common point of failure, replace the sensor with an OEM (Hitachi IS the OEM supplier for this sensor) piece will likely correct your issue unless there's a problem with the harness which is usually pretty obviously damage if that's the case.
I'm going to bet you didn't go with an OEM sensor the last time you replaced it, aftermarket ones are notoriously prone to premature failure.

Clean your harnesses with electrical contact cleaner before reassembly.