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K & N air filter

9794 Views 27 Replies 19 Participants Last post by  hammerma
Have a 2001 GEMS P38. Appr. 78,000 mi. Put in a K&N air filter appr. 2 yrs. ago, at 75,000 mi. Not driven in dusty enviornment.

Been getting amber "check engine" light recently. Code says "too rich - banks A & B"

So after questions on this forum, I changed the spark plugs and wires. Check engine light returns. Now looking at MAF.

Also wondering if air flow through K&N relevant???? It would seem the air flow is better thus engine should not run rich, but any thoughts appreciated.
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Performance filters let more dust through than you would have thought and the Maf along with the engine takes a hammering.

The likes of K&N, Piper etc are ok for boy racers in rice burners cos they dont keep them long so they dont care
The original paper element type filter is by far still the best method of filtration of air by far.....

The Maf will need cleaning and if its been in for along time so will the throttle body and if your lucky your engine
wount start burning oil and smoking soon.

If Manufacturers dont use these performance filters I think that tells us something, even the latest of the AUDI's BMWs, Merc etc dont use them.........that should answer your question and hope you revert back to a paper element soon
Don't dismiss the oxygen/lambda sensors if they are not functioning correctly the ecu could compensate the wrong way and over richen the mixture.


As regards the K&N filter have a look here http://www.knfilters.com/faq.htm#28
ok, i know this is a stupid question, but where are the oxygen/lambda sensors on the 01 GEMS engine?
Performance filters let more dust through than you would have thought and the Maf along with the engine takes a hammering.

The likes of K&N, Piper etc are ok for boy racers in rice burners cos they dont keep them long so they dont care
The original paper element type filter is by far still the best method of filtration of air by far.....

The Maf will need cleaning and if its been in for along time so will the throttle body and if your lucky your engine
wount start burning oil and smoking soon.

If Manufacturers dont use these performance filters I think that tells us something, even the latest of the AUDI's BMWs, Merc etc dont use them.........that should answer your question and hope you revert back to a paper element soon

How would you clean the MAF? thanks.
mark jeansonne said:
ok, i know this is a stupid question, but where are the oxygen/lambda sensors on the 01 GEMS engine?
On each side of each Cat.
mark jeansonne said:
How would you clean the MAF? thanks.
With MAF cleaner. Any local Schucks, NAPA etc should have it on the shelf. Detailed claening instructions can be found with search.
Mark - Isopropyl Alcohol spray is good for cleaning your MAF. Dry it out using a can compressed air (like for keyboards). Don't touch the MAF with your finger or a brush unless you're really gentle and/or prepared to buy a new one.
Cheers, Paul.
viperover said:
Performance filters let more dust through than you would have thought and the Maf along with the engine takes a hammering.

The likes of K&N, Piper etc are ok for boy racers in rice burners cos they dont keep them long so they dont care
The original paper element type filter is by far still the best method of filtration of air by far.....

The Maf will need cleaning and if its been in for along time so will the throttle body and if your lucky your engine
wount start burning oil and smoking soon.

If Manufacturers dont use these performance filters I think that tells us something, even the latest of the AUDI's BMWs, Merc etc dont use them.........that should answer your question and hope you revert back to a paper element soon
Viper, can you substantiate your claim? I've had a K&N filter in my '99 Disco II for 7 years and in my '02 P38 for over a year. I'm a huge fan. In the Disco II, I was getting 280 miles per tank (on avg) pre-K&N and 300 miles per tank (on average) post. This is not an exaggeration. I've never had any problems with either of the filters. This is not to say that I won't tomorrow - KOW. I do clean and recharge them annually.
This issue seems to provoke polarised views like no other (putting aside those that try and botox their front and rear ends to look like a series 3).
I thought I read that Callaway put K & Ns in as standard.

I have had a K & N for a while – maybe a couple of years. Some people say to me the first thing I should do is take it out. Others say it is fine – particularly if you don’t do any offroading or otherwise drive in dusty environments.

But I consistently have the P1179 fault – may be that is due to the K & N - there are threads about this. I will shortly reset it and put in a paper filter for a while and see what happens.

Regards

Andrew (Melbourne)
Thanks all. This is what I found. My stupidity, I neglected my K&N since I put it in 2 years ago. MAF was dirty. So properly cleaned & oiled the K&N and properly cleaned the MAF. Will know in a few weeks if this was the problem, a dirty MAF. Will see if the "check engine" light returns. I think I just need to service the K&N annually. It was dry, needed cleaning & oil. I think the truck actually ran better today, maybe just in my mind, or maybe MAF back to where it should be. Will update in 1 month.
PAULBROM said:
Don't dismiss the oxygen/lambda sensors if they are not functioning correctly the ecu could compensate the wrong way and over richen the mixture.


As regards the K&N filter have a look here http://www.knfilters.com/faq.htm#28
Apologies Paul, but pointing us to the marketing page of the subject at hand can hardly be called helpful or without biased. That's like pointing a Democrat at the Republican home page for assistance.

Many a folk here has been caught in the pocket book by after market "high performance" filter systems. The "gained HP" really is a joke for our rigs. I can get away with that statement after two rounds on the dyno doing testing. K.I.S.S. Keep It Stock Stupid really is the best prescription in this case. Noise under the hood is reduced and risk of fouling your expensive MAF is eliminated. I would have to go back and look, but the HP "gained" was less than 1% or 2% on both rigs tested. I am happy to pay $10 or $12 twice a year for LR genuine filters. You can spend $70-$75 for a system you have to cut your rig apart to mount and then have to go out and buy cleaner and oil for. All that labour at risk of replacing a $1400 genuine LR MAF sensor. NO THANKS
Hi,

I thought I would comment on this. Yes, it is a very polarised subject. I believe that polarisation is due to misinformation and poor maintenance procedures.

1.Some performance air filters may let more particulates through, others will perform as good as a good quality stock paper element filter. Some stock paper filters are not too good either.
2. The MAF will probably get dirty after a period of time whether you have a K&N filter or a paper filter. I will say that if you over-oil your K&N then this may cause the MAF to require cleaning sooner however according to K&N they have tested for this and the test showed it does not happen. If your MAF is dirty or coated with something check your filter and air box etc for leaks.
3. A K&N filter requires periodic servicing, which is low in cost but requires some time. A paper filter requires periodic replacement which is fast but high in cost and not environmentally friendly. This is the reason dealers do not like serviceable air filters, because they require time to service them. This is good if you are a home mechanic (arent all rangie owners? :) )
4. The K&N filter will allow more air flow and filter as well due to better design. I will say that there are conflicting test reports on the filtering efficiency. Who do you believe? well that is the question of this topic. More air flow is probably not noticeable on stock unmodified rangies. Personally I did notice a very slight seat of the pants improvement and a very slight mileage improvement but in defence of my stock filter I would say it was a bit clogged (it didnt look bad though) (Dealer was supposed to replace it! hmmm) I believe that a properly maintained K&N will provide the same engine protection as a paper filter.
5. What is vitally important with both types of filters is that they seal correctly when installed. That needs to be checked and done carefully.
6. A K&N filter is a lot more expensive so it will take quite some time to realise any cash benefit when you buy a K&N. I figure about 4 stock filter changes which is equivalent to the cost of the K&N. (calculated on the filter cost from my dealer and what I paid for my K&N) Stock filter replacement interval is 24,000 miles (40,000 Km), that's 160,000 Kms before you are even.

My personal view is that the paper filter is too expensive so I fitted a K&N. I will be doing the services anyway. If you are having a dealer or mechanic do the work then probably stay with the paper filter, just makes sure that they, A: use a good quality make and B: they actually change it, not just "examine" it.

Oh, and Mark, how did you get a "2001 GEMS" rangie? The "bosch" had them by 2001 and lucas was in the past.

Cheers
Mick
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Thanks Mick – that’s a very useful post.
For those here in Australia, Autobahn does the CRC MAF cleaner for about $30 – although you may have to order it (as I did).
Whereas Callaway I understand put in K & N filters I read in a previous post that Overfinch didn’t change.
The real issue seems to be will the K & N damage the engine irrespective of any (perceived) horsepower gains.

Regards
Andrew
Ha, you got me. I do have a Bosch engine. I wish I could say I posted that as a joke, but really was tired, confused, and more mechanically illiterate than I thought! And yes, good post Mick. My problem was neglected K&N, left it dry, MAF thus got dirty. Golden rule with K&N, I now know, do NOT leave dry, must oil every yr.
The air filter sizes changed several times anyway?

Also read this test:
http://www.bobistheoilguy.com/index.php ... &Itemid=66

Also FWIW, my MAF died very quickly after fitting a K&N element. I wouldn't use one again except on a carb setup.
Hi

Hmmm? This is all very interesting. I have been involved in discussions on K&N filters before. See the "debate" here http://www.rangerovers.net/forum/viewtopic.php?f=3&t=6921&start=15#p49516

I am a proponent of the K&N air filter. I installed the first K&N filter on the '89 Classic I had. There was a very noticeable improvement in overall running and performance. When I updated to the '94 Classic I replaced the standard filter with a proper K&N replacement that fitted in the standard RR air cleaner housing.

Here is the result of a dyno test with standard filter and K&N filter.

[attachment=0:hyr803io]RRDynoChart.gif[/attachment:hyr803io]

You will see that there is approximately a 5hp increase overall (107hp to 112hp) and that the power is improved throughout the rpm band. You will also note that the higher power is maintained for a slightly longer rpm range than the standard air filter, which shows the hp drops sooner. ie ~112hp between 4200rpm - 5200rpm (K&N) and ~ 105hp between 4200rpm - 4700rpm.

Further to this I NEVER had a maf problem with either RR, yet my current 2000 P38 has just had the maf replaced even though it has (probably) never been off-road and has always had it's paper filter replaced regularly (by Barbagallos (shudder)).

I believe K&N filters are at least as safe as the paper filters, do NOT damage the maf and certainly improve the running of the engine and improve power and economy. If the K&N filter is used and maintained PROPERLY according to the K&N instructions then there will not be any K&N induced maf problems.

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mmmm I'd like to see K&N come and say here that there filters wont damage maf sensors...forget it, it aint gonna happen
A larger paper element type filter will also increase performance but I thought owning a 4x4 wasnt about racing....I'd buy a performance car for that

KEEP AWAY FROM THESE DARN PERFORMANCE FILTERS, seriously
It is a polarizing topic, always has been. Anyway, I actually know of someone who's K&N filter came over-oiled from the factory and damaged his MAF past the point of just cleaning it. It does happen, and if you over-oil at all by accident it absolutely can happen.

Aside from the MAF, the facts are that the stock paper filter has significantly more surface area for filtration than a drop in "performance" panel filter and WILL filter better, period. We're talking about trucks that do 60 MPH in NINE seconds, guys. I'll take better filtration, ESPECIALLY on something that goes offroad occasionally, than doing 0-60 in 9.5 seconds instead of 9.6. On my XJR or Bimmers I have always ran performance cone filters (Apexi Power Intake or AEM DryFlow) which I custom built to be true cold air intakes drawing air from down low. But, those cars never saw/see dirt or poor road conditions. And I would never run an oiled filter....forget that.

Just stick with OEM quality paper filters or go all the way on a performance vehicle, but keep it on the road then.
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most people over oil K&N filters thinking it's best, even new ones are over oiled. Mine, new out of the box threw a code with a new MAF. cleaned both and no problem since. I know Mercedes voids warranties if they catch you with a k&N, dirties up maf sensors.

I had my engine uderwater and k&n soaked with muddy water, still worked good
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