Rough Idle P0300 P0304 P0171
 

Hey everyone,

Noticed a rough idle...

Tripped P0171 P0300 and P0304

I have swapped spark plugs, coil packs (from Cylinder 2 into 4).
Tested injectors for resistance 2,4,6 were all same values.
Cleaned MAF Sensornwith CRC
Replaced TB because i heard a rattle noise
Did idle air relearn procedures

Cleared codes but it still idles rough. Cranks starts and runs fine. Revving will drop the idle lower and then it will bounce back up to even itself out.

If this is related I had a cam sensor go out, replaced on the fly with autzone part...not sure if this could cause idle issues but i don't believe so because this did not happen until a week or two later

Any advice? I have a Kinetix SSV manifold and an oil catch can.
I also have Osiris Tuner coming in soon, is it okay to try and have it tuned out?

As you probably know, Nissan engines like to have OEM Nissan sensors. Especially camshaft, crankshaft, and knock. I would suspect that might be causing some issues first. As far as the P0171 code, I would start by checking the connections to and from your oil catch can for crankcase vacuum leaks. Also, check for intake vacuum leaks leading to your Kinetix SSV manifold, as well as where it bolts into your lower collector.

Vehicle year? Mileage?

2005 350z with 170k

I will be swapping injectors today, and re-bolting down my Kinetix SSV
I was told that although resistance in injectors can be good, it may still be clogged or not spraying properly/evenly.

Almost forgot to update!

I picked up a used fuel rail with injectors from a 2003 350z with ~100k miles for $35, swapped it in with my fuel rail and retorqued everything.

Problem is gone!
So lesson is, just because the resistance is good on injectors does NOT rule out that it is clogged/dirty and is not spraying evenly/properly!

Hope this helps those with problems in the future.