No issues with your injectors? If your plugs were that dirty, I'd wonder about injector fouling.

 

So, how many miles were on those plugs?

 

Oops forgot to mention that just under 42K. Judging by the tips I would say they look about 60% worn. Suck that Iridirum tips cannot be cleaned & re-gapped.

 

Hmm you sure you didn't mess up the application of oil on the filter? That is some serious oil and wear on an iridium plug at 40K~, my Altima has a CAI with K&N filter and the platinum plugs
looked about that bad after I changed them (around 100K).

But in any case never hurts to err on the side of caution, filter deff not worth it assuming it's the cause of the issue. It was a good thing you checked on them preemptively.

 

Hopefully, your MAF sensors aren't fouled either...

 

Relevant, for reference:

"We are aware of the "urban myth" (K&N News Story) created by a few dealerships that a vehicle's MAF sensor can be contaminated by K&N filter oil. No evidence has ever been provided to support this "myth" and years of diagnostic testing by K&N has shown that not only is this allegation not real, it is not even possible. In our opinion, it is an excuse for a dealership and/or the vehicle manufacturer to avoid a legitimate warranty repair. In the last 4 years, we have sold over 10,000,000 lifetime air filters and received only a few hundred calls from consumers who are having dealership or service provider challenges."

https://www.knfilters.com/MAF/massair.htm

If you ever have problems with a MAF on a K&N equipped vehicle, you can send them your "bad" MAF and they'll test it for free.

That said, I still prefer dry filters with more surface area over an oil-based filter.

 

What is the part# for those denso plugs? FXE22HR11? Also want to change mine, right at 45k miles. Just wanted to be sure. Thanks!

 

The VQ is known for this. Mine were in rough shape after 60K on the VQ35 with some having a gap of over .06. Replaced with FXE22HR-11 for 2008 G35. The car ended up running smoother and gas mileage went back up.

 

We definitely need to run a good catch can in our direct injection cars. I will do this soon. Been looking for install videos or feedback on a 2016+ Q50RS. We need to vent to intake to maintain vacuum scavenging. So after PVC valve and pre intake is the location, but how and where is the best way to mount one. Hummm

MISHIMOTO BAFFLED OIL CATCH CAN

or the

ADD W1 BAFFLED OIL CATCH CAN V3

I'm still researching this needed install.

 

We definitely need to run a good catch can in our direct injection cars. I will do this soon. Been looking for install videos or feedback on a 2016+ Q50RS. We need to vent to intake to maintain vacuum scavenging. So after PVC valve and pre intake is the location, but how and where is the best way to mount one. Hummm

MISHIMOTO BAFFLED OIL CATCH CAN

or the

ADD W1 BAFFLED OIL CATCH CAN V3

I'm still researching this needed install.

coming from experience with your first choice, I have to say...please stay away from crapimoto.


if you can plumb an AOS, do it. Catch can is just a lot of hassle, but to each his own.

 

Thanks for the great post with photos. I was planning on changing out my plugs at 60k (VQ37VHR) because I dont trust the performance of spark plugs for 105K. This post justifies my concerns.

 

I was just at the dealer and a mechanic said he’s seen VR30 motors needing spark plug changes at 35k. I’m trying to find out the size of the injectors on these cars. Are you VQ or VR?

 

How bad was the access to reach the plugs? Coming from a Subaru, I can't believe they can be any worse, but a cursory glance under the hood and they seem to be buried under a lot of crap.

 

The TB's need to come off but not bad at all doing mine soon I'm at 42K

 

I am quite surprised that anyone runs an oiled filter these days. Check with AEM and cross reference the K&N filter or look for your vehicle on their website.


Since you won't risk knock by running a higher flowing filter, just drop in the AEM. Coming from the Subaru world, it is so refreshing to not have to tune every single tiny change.

 

That's what I would expect K&N to say since they sell them. Interesting they won't guarantee that their oiled filters won't foul a MAF though. Sending them your MAF to test is all well and good but what are you suppose to do in the mean time? Buy another MAF so you can still drive the car while they play with your MAF?

To each their own, but I won't put an oiled air filter on my car. The pressure drop reduction of an oiled filter vs a dry paper filter is negligible and regardless of the impact on the MAF sensor, oiled K&N filters passed more dirt than dry filters.

Testing of K&N vs. dry paper filters using ISO 5011 testing procedures for air filters:

K&N Air Filter Review - Debunking the Myths (and why OEM is better)