Did some searching (lol @ the phreaktor thread leaving the plastic bag on the filters) but couldn't find a definitive answer so I figured a thread was in order addressing my specific situation.

Vehicle : 2007 350Z with 20,000 miles
Engine Modifications : None, 100% stock
K&N Drop-in air filters PN# : 33-2399

Purchased the 2 new filters and installed without any issues (4/4/2012). Started the car and allowed it to warm up to operating temperature before taking it for a short drive around the block. Everything ran properly without any problems.

Fast forward to the next day (4/5/2012).

The car sat in my garage during the day while I was at work. That evening I went to start the car and immediately after ignition the car was experiencing a VERY rough idle. I turned it off and restarted to the same result and within 30-40 seconds my “Service Engine Soon” light illuminated so I quickly shut off the car. Opened the hood and inspected the intake system including the air boxes. Everything appeared fine. Not sure what to do next, I removed the K&N filters and re-installed the original paper filters. Started the car and immediately the idle was back to normal and the car ran perfectly fine as it did before the K&N air filters.

Drove the car to work this morning without any problems but my “Service Engine Soon” light is still on and I have 2 new K&N filters sitting in my garage instead of in my car

I contacted K&N via email last night (no response yet) and just wanted to know if you guys had any thoughts/suggestions on clearing my SES light and getting the K&N filters to work properly.

 

you need to scan the codes first, doesn't make sense to clear it without knowing what they are

 

Yeah I agree, it was late last night when it happened but was going to try today to get somebody to pull the code.

It just seems weird that it appears to be specifically related to the K&N filters since after re-installing the paper ones there has been no issue.

 

Only thing I can think of is that the K & N filter may have had some sort of oil (for the filter) either on it already or applied by you that may have flew in to the MAF sensor .

When I bought my M45, the forum I joined mentioned some popular issues with the car and one of the leading issues was issues regarding K & N 's filters with the oil they use flying in to the MAF sensor and fudging things up.

If this is the case, I don't know if cleaning the MAF is necessary or replacing it but of course you can consult a dealer or repair shop for the solution if the MAF sensor is the problem.

 

^ The MAF sensor was my first thought since I've also read of this issue (even new ones out of the box which these where) but I would think if that was the case putting back in the original paper elements would still be giving me the same problem.

Also found a guy here at work that has a scanner so hopefully after lunch I'll have the error code.

 

That is weird. Good luck.

 

Well at least it's not just me that thinks if f'in weird, lol.

Thanks for the input BB.

 

Yup. Just don't drop a turbo in your car. It would probably spontaneously combust.

 

With my luck??.......yes, you are probably correct.

 

Well.....went to get gas @ lunch (SES light still on) and after filling her up and restarting the light is now OFF. So I don't know if it automatically reset since it's been running fine with the paper filters or if it was some freakishly coincidental gas cap deal

Either case the light is off and now I just need to get the K&N filters working correctly. I'll give it a go tonight after work and see if the rough idle is still present.

Stupid question incoming.....

Is there anything "special" I need to do when installing or should I be able to just drop them in and go (what I did initially)??

 

This is a really straightforward install, just take your time and make sure anything that you unplug or unscrew is put back to stock before starting up your car after.

You might have inadvertently did something prior

 

K&N is very adamant that their filters and oils don't damage MAFs. This link has some info. http://www.knfilters.com/warranty.htm


Make sure you don't have the MAFs on backwards, that all the plugs are in properly, and that the airbox leads are installed properly and sealing correctly.

 

MAYBE YOU ARE PUTTING THEM IN BACKWARDS???
Your problem just does not make sense?
By any chance,are you STARTING your car or have the IGNITION ON when
messing with this install?

 

Its a simple filter and not the cause of your problems.

 

They may be very adamant but it doesn't help when heaps of M45 owners complain about K&N filters and avoid them like the plague.

 

From personal experience, those fears are unfounded. I've ran K&N stuff on several cars and had no issues.

 

I've ran K&N stuff on other caras as well and yes, no problems.

When I first bought my M, I joined a site with other owners of the car and saw posts stating to stay away from K&N. Better to be safe than sorry especially with a car where replacement parts can be pretty expensive.

I ended-up with a factory Nissan element.

 

Update

Re-installed the K&N's last night after work, fired it up and everything was 100% normal. Took her out for a fairly lengthy/spirited cruise and it ran like a champ. Just did the same thing this morning and she's still running fine.

To summerize....

~ Installed K&N's, short drive, ran fine.

~ Next day, started with rough idle/SES light came on. Replace K&N's with paper elements, everything back to normal.

~ Next day SES light goes off, re-installed K&N's that evening, long drive & ran fine.

Not sure WTF caused my problem since, as mentioned, it just a damn filter which in my 40+ years I've never had any issues replacing (including K&N's). After corresponding with K&N support (which is great by the way) they suggested I didn't drive it enough on the initial install to let the car adjust to the increased air flow causing the rough idle at startup 24hrs later

Whatever the case.....it's running fine now just wish I could have had a more definitive cause & effect solution in case others have the same problem (lol, doubtful).

Thanks for the replies/suggestions.

 

Since all is good figured a bath was in order.

Obligatory pics......

 

i was gonna suggest disconnecting the neg battery cable for a lil to reset the ecu, thinking maybe the new filter did somehting with the MAF sensor, but no need it fixed itself