Hey everyone. I’ve got a 2009 Infiniti g37 coupe that’s been acting weird.

so I was driving home the other night and after cruising on the highway coming home from work, I put the car in neutral so I could come to a stop after being on the highway. As I put the car in neutral as I was rolling, about 10 seconds later, the car just shut off. Only the engine though. Everything else was on. I drove the car a little more and watched the rpm as I put the car in neutral again as I came to a stop, and it was bouncing all over the 1k-0 rpm range. Here are my observations from the cars info it gave me from the obd2 scanner.

ltfts: normally around -10

maf gps: at warm idle is around 5.3

o2 sensors upstream: 2.2-2.0

no vacuum or exhaust leaks.

code for p0300- random misfire. Rarely ever stores. CEL will flash sometimes but never store a code and turn the CEL on. Never felt a misfire when the CEL flashes. It drives perfectly smooth.

o2 sensors downstream: fluctuate at 0.8-0.01 it will slowly walk itself from 0.8 down to 0.01 then go back to 0.8

sometimes when I put the car in neutral as I roll getting ready to slow down at a stop sign or whatever, the car will go in open loop, than closed loop and both bank stfts will lock itself at +25 while my foot is off the gas and go back to normal ish readings once I’ve stopped

cars oil smells like it’s got some gas in it.

at idle before driving, cars exhaust smells rich and gas like, but after a drive it sort of smells like a scalp/hair 😂

laggy throttle in first gear when I first get going than I absolutely fly. Feels kinda like I’ve got turbo lag lol

I’ve replaced every imaginable part. Fuel pump, injectors, maf sensors, o2 sensors, spark plugs, coil packs, vacuum lines, gaskets, exhaust gaskets, intakes, you name it.

I called a mechanic that specializes in Infiniti/ Nissans. He told me he’s seen this exact problem before multiple times and never found out what the cause was. He told me I’d be better off going to the dealer. If anyone could help me, that would be amazing