Thanks - hopefully I'll get back to it soon. It would be really nice if there was a rent-a-garage shop around my area so I could work on my car easier, especially with this arm.

 

check your intake boots for cracks too. both my accordion style one by the airbox and the coupler in front of the throttle body were both cracked badly due to age. i am amazed how well the car ran with such air leaks. i don't think an intake or exhaust leak would just affect cylinder 6 though...

 

So yes, I do have a rip in the accordion as well (had it for a few years) but it doesn't make a difference for me when I plugged it. I also have a tear near the TB but it also doesn't make a difference either.
I sprayed brake cleaner around the engine bay and got no results.

 

Update: I am out of a sling and can drive. I put in a bottle of Gumout Fuel Cleaner with the PEA, and the misfire occurs much less. Maybe once every red light instead now.

So what does this mean? Well, assuming that the Gumout probably is increasing the octane, it is basically delivering more fuel to the cylinder. This means I'm either getting in too much air or not enough gas in the cylinder.

Time to check the injectors/air intake.

 

UPDATE: Injector cleaner did nothing. I hooked up the OBD reader to the car and I'm getting around 10%+ fuel trim to both banks. I'm also getting 0.3V on o2 sensors for 1x1, 1x2, 2x1, but 0.6v for 2x2. This makes sense - the air low voltage on 1x2 is due to engine running lean. 0.6 on 2x2 is the engine dumping gas into the 2nd bank.

My guess now is that a rip in the intake tube is the culprit - I have an eBay CAI on the way and will replace the G tube with the one from the cheap intake. Theres a decent sized gash in the accordion tube and a small crack in the coupler connecting to the throttle body.
I've noticed the car is starting to run hot, although the temperature meters say otherwise. I think the car is running lean with the post-MAF rips in the intake. This makes sense with the P0306 code because its the closest cylinder to the throttle body. This means that it gets first dibs on the air coming in the manifold and its clearly being overloaded.

I will get it and install it on Tuesday and report back here.

On a side note, I also to replace the other A arm to replace as well as the other front sway bar bushing. Passenger brakes need lubing and for some reason the driver headlight was sticking on the highbeams for a few days as well as the battery light coming on very faintly for a few minutes the other day....

 

So I installed the new intake - didn't fix much at all. The exhaust is louder that's for sure.
The sputters are still there - I'm starting to think its just an exhaust leak and nothing more to be honest - I get sputters when the idle is at 650 especially.

Any ideas??

 

I still think it's a misfire of some sort.

Have you looked at the fuel dampers?

 

No I haven't - what are they?

 

https://www.reddit.com/r/350z/commen...senger_engine/


Also see this thread.. https://g35driver.com/forums/g35-cou...you-think.html


We have one on each side of our cars. https://www.rockauto.com/en/catalog/...re+damper,6120

Probably a long shot but it can cause a misfire and it is a part of the injection system.

 

I'll have to diagnose that and see if it makes a difference then.

Here's another video with the noise - the camera is just inside the rear driver wheel beside the exhaust.

 

Update: The code has turned into a confirmed P0300 with the CEL light coming on.

I'm out of town next week - taking it to a mechanic the week after. I am so fed up with this car....

 

I feel your frustration, this would drive me nuts. Did you test the fuel pressure and fuel dampers?

I think it's time for a compression test, it's about the only think that wasn't done.

 

I don't have access to a tester. However I gave the damper on the passenger side a good whack with a wrencb and it stopped misfiring for a minute....

I'm gonna take it to the mechanic on Saturday and see what they say.

On the other hand I did the following this week:

- My transmission cooling line was all rotten and rusted out. I noticed it was leaking around 25ml of fluid every night and leaving spots all over the driveway. The other day I felt like the tranny was slipping so I went to the mechanic and had that replaced for $650 all-in right away. Didn't solve the misfire.

- My undertray was all ripped up. A new undertray came in today from RockAuto. Now I gotta go to the Home Depot to get some new bolts for it!

While I was at the mechanic for my tranny leak, they noted that my resonator also has a leak - will cost $300 all in to replace.

 

Well that's interesting. Hopefully it's a quick diagnosis in the fuel system. Could the resonator cause that sputter?

 

FIXED:

Took it to my mechanic - apparently the plugs weren't gapped properly (0.07 vs 0.43) even though I bought them pre gapped. 4 plugs were also loose.

The issue is fixed! No more misfire!