Steve Fort

After having my HKS induction kit fitted for 2,000 miles, my MAF senser decided to give up the ghost, conveniently when i'm 300 miles from home!
A 300 mile drive in a scoob is very frustrating when you have to keep it off boost, i can tell you!

Anyway, it is deinatly the induction kit that has caused the damage through poor filteration/oil particles from the foam, as the OE fiter managed 20k without damaging it, and if it was damaged whilst fitting the kit, i'm sure it would have shown signs alot sooner.

Even more pissed off when my local dealer told me that a replacement is going to cost over £300!

Before fitting the new MAF senser i want to replace the HKS with something a bit kinder to it. I cant refit the air box because of the FMIC being in the way.

Any ideas of a safe replacement? Have there really been no probs with K&N induction kits on MYOO turbos?

Cheers,

Steve

boultsy

Steve, started talking about your MAF failure in another thread Blitz, K&N or Panel? and madness posted a link to a filter review thought you might be interested.

Bob Rawle

Despite all the filter reviews the fact is that if you upgrade your car then you stress components. the MY99-00 hot film MAF is renowned for failing due to excess vibration, this is the main cause not poor filtration. K & N filters seem to be better than some for filtration but that will not guarentee your maf will not fail. Some companies do offer that assurance but its done on the statistical basis that the guarentee will generate higher volumes of business which will sustain the warantee costs. (no offence to any company intended here)

barge

Are you sure its the filtration that caused it ??

My HKS induction kit has been fitted for over 24 months & nearly as many miles, I have the grill above it open all year round with out [touching wood] any problems.

Andy W

Steve,
check out
http://www.macspower.net

He will guarantee your MAF.

Andy

Scott.T

iTrader: (2)

can I view macspower.net without installing Flash 5.0

My company laptop won't allow me to install anything !!!

john banks

HKS is renowned for MY99/00 MAF failures. K&N is not. It also has a mounting to the coolant reservoir which may reduce vibrations. Still don't think it is any quicker overall than an ITG panel though hence I run that now - possibly better torque low down but slightly less top end compared with induction but a heck of a lot quieter.

Bob Rawle

Can you point us all in the direction of the evidence for that statement John ? I would agree that K & N is a good filter but having run with an HKS for over 50,000 miles with no issue I am "slightly" interested in where this came from ... now if you had said Blitz .... btw magazine reviews are not what I had in mind. Be under no illusion that I have an interest in that BRD is a HKS dealer, if the product is no good however we would like to know. BTW I have also used K & N for in excess of 100,000 miles on previous cars with no problem. The ITG is renowned for dripping goo into the air box that could contaminate the maf so be aware that may also cause you a problem (possibly). IMHO and all that.

cheers

Bob (currently using an APS cold air induction kit cos that's the only thing that fits with the APS FMIC ... )

Muncher

I've had a Blitz induction kit on my 95WRX for around 20,000+ miles now and no problems (reminds me, I must give it a clean ).

I think my MAF is the wire type rather than the later film type though.

Am I right in thinking there are two type of MAF ?

Giles.

john banks

It is not evidence in terms of a randomised controlled trial or equivalent Bob, but the number of people that have posted on here with MAF failures who were using HKS and also one individual case where someone had three consecutive MAF failures within about a month with properly fitted (a mechanic who did it himself) HKS on a MY99 does make you wonder (the MAF sensor was replaced each time). If not a proper trial then at least with the number on Scoobynet who fit induction kits, you are quite likely to hear about failures perhaps more than being one individual dealer? You do not have a trial with complete groups of similar cars and then follow them all up for 2 years or so, but have the manufacturers actually done this on every car model available? You have to go off the best evidence available. If you have any better let's hear it... but an "n of 1" trial of no failure yourself in 50000 miles does not add much statistical weight even though we don't have all the denominators to work out failure rates with confidence intervals. Often you have to go off incomplete data and make assumptions. A filtration test or any lab test cannot tell you whether the mass market of consumers using the product on a car will experience failures.

Do you still have a MAF sensor on your car?

Maybe I am only regurgitating misinformation again if so apologies, but misinformation is not necessarily so simply because it is not a professional's opinion or quoted from official sources - how about consumers and their experiences - possibly the most valid of all?

[Edited by john banks - 1/27/2002 10:26:28 AM]

john banks

You will get as many opinions on this as you will retailers selling different brands, but Cobb tuning (who I think sell products of all the brands in question if not induction kits of them all say this: http://www.cobbtuning.com/tech/airflow/

"MAF Sensor Failures
While this air reversion might cause erroneous readings of the air flow meter, it's not solely responsible for their failure. No one situation can be contributed to the high failure rate seen with the 1999 series MAF sensors but rather a combination that is the cause. Our opinion is that the number one cause is vibration. Many of these aftermarket intake systems and even turbo kits do not properly mount the sensor in a way to prevent them from receiving quite a bit of vibration. As you drive, the engine bounces and vibrates around which is torture on the electronics inside the sensor. We've even seen some kits which bounced the MAF sensor against the engine bay whenever the engine torqued over. Other various reasons have to do with poor intake filtering, sudden pressure changes (ie: blow off valves shooting hot air into them from the back side), and heat.

How do we solve this? Well, we have to understand we're dealing with a delicate, precise piece of electronics that needs to be treated with some care. First, properly mount the unit firmly to the body and use rubber bushings between the MAF sensor mounting bracket and body to reduce vibration transferred through the body. For those of you who want to instead mount it to the engine, make sure you don't have a problem with the MAF sensor hitting anything else in the engine bay and use the same rubber bushing trick to dampen the constant vibration the engine produces. Second, use a quality filter element. Cloth elements from K&N, A'PEX, and others work well when properly oiled. Even foam elements from Amsoil, Greddy, and others do a fair job of filtering. We recommend against using HKS filters and Weapon-R filters as we've had too many instances of foam degrading and getting into the intake tract (they also don't filter very well). The absolute worst though are the Blitz Stainless Steel filters. These might look better than just using chicken wire but they filter about the same. Lastly, if you're turbocharged make sure you run a blow off valve but don't have it discharge right into the backside of the MAF sensor. It doesn't appreciate too much when you do that."

All opinion of course and a shame search is off too as there are many other varied opinions on the topic.

So I don't think my statement is invalid, but if you show it is Bob I will withdraw it.

I am not saying K&N does not cause MAF failures. I was merely pointing out that HKS on the board seem "renowned" for it and K&N don't. Just my reading of the contents of the BBS as what I hoped was a helpful summary.

How is the HKS mounted?

[Edited by john banks - 1/27/2002 10:59:04 AM]

Bob Rawle

Thanks for the link and cut and paste, I have no reason or inclination to suggest that you need to withdraw anything, in reading your post I was 1) interested enough to want to add the info you had found to my own, 2) as I do, wishing to support what I consider a good product or products and 3) to make it clear I was speaking from my own experience of the use of both HKS and K & N filters both of which I consider good.

My comment about my own usage is of no relevance other than to provide some further information, having used Blitz, K & N panel, K & N cone, HKS Induction and Suction plus ITG cone and panel filters.

The Cobb experience is similar to mine and others in that the main cause appears to be poor fitting allowing mechanical vibration to upset the maf, the hot film of the MY99-00 cars is particularly susceptible although this design has been used in many other vehicles without real problem. Earlier cars do indeed use a hot wire type which is more robust and less susceptable to both vibration and contamination. Poor filtration causes contamination and erroneous readings which obviously confuse's the factory ecu, Blitz is definately bad news on that front. If three maf's failed in a short period its pretty obvious that something was consistently "not right" but it could have been simply that the filter was full of gunge which caused the first to fail which would obviously perpetuate if not noticed. Most after market filters are said to not need changing for long periods, thats fine for aspirated cars but in a turbo car the filter needs changing or cleaning every 10,000 miles .... just my own experience and thoughts.

Those people running aftermarket ecu's can, in most cases, remove the maf completely for safe keeping as it is not used. Mine has been out of my current for maybe 50% of the time that I have owned it, on the previous car it was left in place the whole time.

I have come across maf failures under all sorts of circumstances including when still using the factory air box.

The HKS is provided with brackets for mounting that are intended to ensure that vibration is not an issue. Thats not to say its a perfect system, nothing is. As you say pity the search is off as the subject was very well discussed maybe a couple of years ago. The mechanical vibration issue was considered to be the main culprit then as well.

If you have a warranty on a UK car then you need to stick to the factory filter ... anything else will probably void your warranty, unfortunately that is not conjucive to the never ending quest for more performance that some (including myself) seem to find irresistable.

cheers

EvilBevel

Bob, small thing.

>>the hot film of the MY99-00 cars is particularly susceptible although this design has been used in many other vehicles without real problem

I have it from a good source that the MAF on the Seat Ibiza TDi (which looks remarkably like the hotfilm sensor on the MY99/00) fails quite often actually, percentage wise moreso than on the Impreza.

Theo

john banks

Sorry Bob, I was perhaps rather aggressive in my posting. Lets say I have wound up a few people recently by trying to publicise facts that some people knew and kept fairly quiet about but the majority seemed not to and was genuinely concerned people have been sold "lemon" equipment. I prefer to keep the debate technical and don't want to contribute to rubbishing any product unless there is good reason to suspect it is not the best choice or substandard. I never know how much to back up what I say, but I do think carefully before posting, and many have criticised my posts for being too long! I, like Chiark and no doubt others searched all the boards from day one when choosing an induction kit and we both settled independently on K&N because of what we had read through hundreds of postings. Some of it may be opinion or "amplified rumour" that started as Chinese whispers, but when K&N is about I would go for that over HKS and recommend the same to anyone that asked, although there are probably risks with them all, even ITG panel with the goo issues again possibly relating to fitting.

I have huge personal respect for you, what you post, and the products you are offering although have not (yet) been a customer. But whilst you properly map ECUs and do a fine job from what everyone says, good on you. I always point people in your direction and will continue to do so (as long as you don't start selling crap ). Possibly because of posting volume and helping a lot of people out although I am only an amateur a lot of people do ask my opinions on things often in areas I am not able to comment on, and I seem to be receiving a lot of emails about boost control with several thinking I run a tuning shop!

I am getting emails from all around the world about this boost controller and wish lists etc etc. I tell them only to do it if they are capable of it and to add the features they want.

Apologies again if I offended, and again I appreciate all your help in teaching me a lot.

Now thread back on track....

Mac's Power

Hi Guys,

Sorry that I havn't had time to post recently as we are very busy since opening the new premises

Thanks for the referral Andy......... Passenger laps secured for Kirkistown on the 17th....

With regards maf failures.......we have done extensive research into the problem as I've had 3 MAF sensors go in my cars. The only solution that we found was a KIT from STI with a pink trumpet thingey. The Kit itself was very very expensive so K&N made a custom cone for it....much larger than a standard K&N.
I fitted it to both our cars and never had a problem since. I'm not currently using the maf sensor on the MY00 due to a LINK (thanks Bob) but both cars have done 40,000+ miles with no problems.

This is not the basis for giving a maf sensor guarantee but the fact that we have sold over 30 systems with no problems whatsoever.
I'm sure other manufacturers can also "boast" these figures but we're prepared to stand by our system and give a guarantee. Your right Bob the guarantee has boosted sales but still no maf sensor failure......... and that includes cars that have previously tried everything. Our system might be more expensive than others but a maf sensor is also expensive.

Paul.

Bob Rawle

John, no problem, I for one enjoy your posts, its the sort of thing the bbs used to be known for.

Paul, I liked your filter set up as well, you have done the research and are prepared to back up the product.

Theo, I'm not trying to imply that there is no problem with the hot film just that its not special to Subaru, I'm sure other vehicle makes have similar issues for similar reasons.

As John says, back to the thread.

harvey

iTrader: (48)

Last week before this was raised John Banks pointed me in the direction of Bob Rawle & I ended up speaking to Branko. Now assessing/looking for the best induction setup &engine management system for STi Ver 6 Wagon. 3"D.P+decat exh+K+N Pannel+Forge BOV recirc + ported exh+lightened flywheel. Other views or advice greatly recieved. P. Croney, Mike Tuckwood & today Paul MacLoughlin all spoken of BRD in highest terms.

pob on the job

I lost 2 maf sensors in 5k miles. An HKS induction kit was fitted to the car from new and both failures occured during this time. On both occasions the failures occured as I backed off the throttle from high revs. I nearly went for a link ecu.

I struggle to understand how the vibration theory as the K&N was fitted in exactly the same way as the HKS. Unless the brackets holding the HKS (via anti vibration mountings) actually transmit rather than prevent vibration. The K&N doesn't have these brackets.
I spoke to Paul and he recommended the Sti/K&N. This set up is not the cheapest, but cheaper that a new MAF sensor if you need to replace it. I have found the kit to be excellent. For what it's worth I've done about 10k since and had no problems.
I'm not saying that the HKS is no good, because I really don't know. There are lots of theories around from vibration to reverse airflow.
What I would say is I have had no problems with the K&N/Sti set up.

Andy Tang

iTrader: (3)

I have a friend who blew 3-4 MAF sensors in a month! The fitting of the kit was fine, as this was checked by two independent mechanics.

He was running a HKS induction kit and that was thought to be blamed, until I asked how long the element was on the car!

Apparently it was on for 30,000-ish miles and it was second hand when he got it!!

So how many of these HKS failures are down to poor servicing?