After Exhaust & Air Filter replacement, transmission seems sluggish

[Rob-bb]

hI. I upgraded my exhaust system in a Fuga 450 (M45) and the intake filter with a K&N filter. Not yet been tuned after the upgrade.

Now the transmission seems sluggish to change gears, after accelerating to about 80kph (50mph) and then backing of the throttle it will take a few seconds and change up a gear then a few seconds later change up another gear. Also some times when driving around town in the the 40 to 60 kph speeds it seems to some times pause between gears, or change and the it feels a bit rough engaging rather than a smooth change.

I dont think it is related to the exhaust change but it literally happened after the drive to the shop, get the exhaust changed, drove home and noticed it.

Any thoughts on what is happening, is it just a coincidence like I assume or is it possible for this to effect the transmission changes in some weird way?

[EdBwoy]

Is the K&N filter an oiled filter?
If so, start there and install a regular dry filter. Most nissan mass airflow (MAF) sensors don't respond well to such filters, the particles trip them out and they could eventually completely die.

When was the filter replaced in relation to the transmission lag/ exhaust issue?

And do you mind describing what exactly your exhaust upgrade entailed?

The car computers have specific parameters that they expect to operate in, so your might not have messed your transmission, it is just not as snappy as before since the ECM might just be telling the TCM not to react yet.

[macgiver]

mac , I hope this isn't what happened ,but I know people who somehow- like through the grapevine - found out that "shop monkeys" beat the livi 'n CRAP out of their car ? Their idea of a TEST RIDE from HELL .

[Rob-bb]

Um, the Filter was added at the same time, and the oiled filters breaking MAF sensors is a myth I believe (at least these guys convinced me it is a myth https://www.youtube.com/watch?v=gE6moItrZNg). And I trust that the guy didn't thrash my car, if he did he must have only traveled less than 100 meters (about 100 yards) or reset the mileage

The upgrade, cut the pipes between the Oxygen sensor and the second set of cats, run 2.5 inch pipes to an x-pipe, and back out to mufflers. So it still has the cats built into the exhaust manifold and the Oxygen sensors.

[Rob-bb]

The car computers have specific parameters that they expect to operate in, so your might not have messed your transmission, it is just not as snappy as before since the ECM might just be telling the TCM not to react yet.

If it is this would a ECU tune solve it? I am planing to book one next week anyway due to the exhaust replacement.

[EdBwoy]

Um, the Filter was added at the same time, and the oiled filters breaking MAF sensors is a myth I believe (at least these guys convinced me it is a myth https://www.youtube.com/watch?v=gE6moItrZNg). ...

Then, in that case I recommend you take the car to a dealer to diagnose your issue. We can only tell you how our cars behave with certain modifications.
Good luck

[EdBwoy]

The car computers have specific parameters that they expect to operate in, so your might not have messed your transmission, it is just not as snappy as before since the ECM might just be telling the TCM not to react yet.

If it is this would a ECU tune solve it? I am planing to book one next week anyway due to the exhaust replacement.

Maybe. What I am saying is that you received a perfectly engineered item and chose to make changes to it. For it to act normally again, either trust millions of Dollars spent on development and heed the manufacturer's maintenance recommendations, or pay someone a few hundred to try and reprogram things. It will change something alright, but I can't say if things will get better or worse.

[Rob-bb]

It's going to be tuned anyway so I will wait and see if it settles down, there are no check engine lights on or anything like that and it has only done 20km since the upgrade.

[amc49]

I have actually cleaned messed up MAFs myself after exposure to K&N oil to have them go back to working fine after. In fact I've had to change plugs themselves when the oil fouled them to miss. I used to sell K&N and the first thing I found was that once the oil level in the filter is pulled down from say a month of use then take the filter and hold it up to sunlight, you will easily see all the small dots of sunlight that dirt leaks through like the filter is not even there. The oil is supposed to trap any dirt there but once the filter pores open up any dirt particles smaller than the holes in the filter go right through like the filter is not even there. If the dirt never touches oil it does not stop. I used to be a big user but I won't touch them now.

Nobody says a word about how a paper air filter sets up a certain pressure drop and the K&N totally changes that and the MAF software is set in place with the restriction of the paper in mind. Meaning your fuel map is no longer right with a K&N even with all the learning an ECM can do. K&N filters will so destroy the metering on CV type carbs due to the change in pressures they are not recommended for them as often the fuel/air is no longer easy to set. Some can but others become impossible.

The OP issue is more likely to be the filter than the exhaust, cars now use the MAF info for everything to do with ATX shifting, it is a load indicator. And no way will I buy the K&N defense even though car dealers will lie as fast to blame the product. One either understands that when the filter is new there will be a certain amount of oil pulled off of it until the filter hits the longtime running condition and it hits the MAF and the MAF to work correctly needs to be perfectly clean, or they simply don't. K&N can foment opposition to that till the end of the earth and it changes nothing.

[Rob-bb]

Nobody says a word about how a paper air filter sets up a certain pressure drop and the K&N totally changes that and the MAF software is set in place with the restriction of the paper in mind. Meaning your fuel map is no longer right with a K&N even with all the learning an ECM can do.

Yes, I know about the flow changes etc, hence car being sent for a tune next week. So the MAF is used by the system to calculate gear changes etc, that is good to know and probably does explain the change in shifting behavior and why it happened immediately after the exhaust and filter change.

Thanks for that info amc49

[Ilya]

Um, the Filter was added at the same time, and the oiled filters breaking MAF sensors is a myth I believe (at least these guys convinced me it is a myth https://www.youtube.com/watch?v=gE6moItrZNg).

My wallet confirms the myth is not a myth but indeed fact.

K&N filter took out two separate MAF's on my 1999 Maxima as well as numerous other MAF's on Maxima.org. Brand new filter pre-oiled from factory, not one that was incorrectly re-oiled. I'll never use an oil based filter again. I'd rather change paper filters every 100 miles than use that crap.

But as Ed said, if you don't think that's the problem next visit would be a shop or a tuner, but no guarantees there.

[Rob-bb]

I know a lot of people blame the filter for maf failure, but logically it cant be becasue Americans would have sued them into the ground if it were true, they have that culture of suing companies for millions when the coffee is too hot

Joking aside, it does make sense that altering the air flow could make the ECU think the engine is under more load than it is and result in the car holding the gear longer. I will find out and report back if I find anything interesting.

[macgiver]

mac , Interesting aside on the K&N , I got em and always wondered about the effects of that oil , I am now
"edumicated" on that ( Uncle Jed )

[szh]

Um, the Filter was added at the same time, and the oiled filters breaking MAF sensors is a myth I believe (at least these guys convinced me it is a myth https://www.youtube.com/watch?v=gE6moItrZNg).

Your decision and your car, but it is not a myth for Nissan engines.

The MAF in these is a hot-wire measurement device. So when the filter adds its ultra-fine micro-droplets of oil (invisible for all intents and purposes otherwise) into the air-flow (and, yes, it WILL do so, no matter how little oil you think you have used), these oil particles deposit on the hot-wire and "burn" themselves on.

In time, depending on how much oil is on the filter, the MAF dies ... and, there is no way to clean it either.

On our Infiniti and Nissan engines, with their hot-wire MAF design, you should never introduce oil particles into the air stream.

Z

[Rob-bb]

This is one of those things were you get both a yes and a no answer from the internet, but there are plenty of people who claim MAF's can be cleaned https://www.youtube.com/results?search_ ... MAF+sensor and a google search for "nissan K&N filter MAF Sensor" does not bring up a lot of people complaining that it broke.

So I guess I am going to find out

[EdBwoy]

Please let us know how it all goes.

This is the way I see it:
OEM filter
- costs approx US $20. part #16546-EH000 for the V8
- was designed and is guaranteed for the car by the car manufacturer
- designed to be single use.
- remove and replace in kind; a 2-minute job and nothing else needs to be tweaked

K&N filter
- costs approx US $70. part #33-2398 for the V8
- claims it is designed to increase power
- designed to be reused
- will take a little longer when it is time to do maintenance, requires careful oiling
- might or might not permanently damage your MAF sensor
- will most probably require you clean your MAF sensor at some point
- might affect your driveability, transmission behavior etc
- will definitely affect the parameters at which your engine operates, so might need to pay for tuning

It is not my style to
1. buy parts that cost more and are not guaranteed to be better than OEM spec
2. add more steps to my maintenance routine with no measured benefit
3. have to pay even more money to make my car operate the way it was meant to in the beginning because I changed something
4. all the while taking the risk of ruining other parts

It is crazy what a mere paper filter will do to our cars: post6764816.html#p6764805


This happens in a lot of different situations, but to bring the point home; it could rub forum members the wrong way when people come to a Nissan car forum and trash the experience and knowledge of people who own, operate and maintain these cars. Yet, people will not question why a study commissioned by an aftermarket air filter manufacturer finds no fault in them.
I am not a filter manufacturer, and have no financial or emotional incentive to steer you away from any brand of filter.
I hope you understand that is true for most of us on this forum, but we are willing to learn if honest data is presented to us.
It is from the same experiences like Ilya shared that we learned to stick to NGK spark plugs in recent model Nissans... or to only use OEM thermostats.


All we can offer is advice and our experiences, and you are welcome to go against it - I don't take it personal. Thanks for offering, I look forward to your updates for the sake of posterity on the forum.

[Rob-bb]

This happens in a lot of different situations, but to bring the point home; it could rub forum members the wrong way when people come to a Nissan car forum and trash the experience and knowledge of people who own, operate and maintain these cars.

I didn't come here to piss you off, It appears I dont fit in here well and thats ok too, thanks for your time anyway,

[EdBwoy]

Nope! I did not say that about you as a person. A lot of people have contributed to your other threads, including me. We all want more from our cars, and people are taking time to help each other not get screwed over in the quest for more.

You picked that one line from my entire post, in which I also said I am willing to learn from your experience and would be waiting for an update. Don't let the opinion of one stranger on the internet affect your decisions and participation in the forum.

It can be hard to convey true context through reading text, but you will notice there are no angry words. In my desire to learn and educate, I have gone to online sellers to gather objective info to put in my post so it doesn't look like the ramblings of some angry person... and I even put up an extra link if you care to read it. I am not pissed, and we can agree to disagree. The line you have quoted was my reminder on online etiquette (and you guessed it, you can choose to ignore)

I wish you an enjoyable ownership experience with your car.

[pedsemdoc]

I think Ed has put it most eloquently -

We all want more from our cars, and people are taking time to help each other not get screwed over in the quest for more.

it's very difficult to judge the intent and context from someone's written comments - so many clues can be gained by seeing someone's face and the "micro-expressions" (I think that is what they are called) to know if someone is joking/lying/sarcastic/truly sincere.

our forum tends to be very civil due to our moderators, we can often AGREE to DISAGREE, and everyone is entitled to their opinion. Even some of our members who are Infiniti/Nissan techs don't summarily dismiss folks.
We have had some experienced members change their beliefs after being presented with additional evidence/proof/examples that often contradict what they thought was irrefutably true

You seem like a genuine bloke, we don't have many members outside the North American continent, don't feel like we're shaming you into leaving the forum, collectively we are stronger as a group and we all are entitled to our opinions. Just don't dismiss some one else's experience as fiction. We are all here to learn from each other and to make our cars even better than before.