Re-Bitten Hero

Updated list:

Re-Bitten Hero : MY00 PPP 50,000 miles - Engine blown
PTMW!: MY99 PPP 77,000 miles - Engine blown
drb5: my99 44,500 miles - Engine blown
SiDHeaD: MY00 (?) - caught before engine blew
Scoobygav555: MY00 - failed entirely and had CEL
IN THE STICKS: MY99 36,000 miles - failed completely and replaced (TBC)
CraigH: STiV - failed MAF may have caused engine blowing
scoobymoo: MY99 PPP 36,000 miles - MAF and Lambda sensor replaced due to bad idling
Iwan: MY99 41,000 miles MAF sensor replaced due to bad idling
Soapy Sam: MAF sensor replaced as it was failing
EvilBevel: 4 MAFs failed totally, 2 failed gradually; engine saved by KnockLink
scooby-zeus28: (no MY or miles given) - failed totally with CEL
ScoobyDoo555: failed MAF sensor replaced after engine blowing and bad idle
Flat 4x4: MY99 55,000 miles - MAF unconfirmed, O2 sensor replaced due to bad idle
akshay67: MY99 - MAF failed, identified from bad idle after ECU reset
donutman: probably MAF causing two engine blows
John WRX: 2 MAFs failed (one gradually, one fast)
adge: MY00 PPP 23,000 miles - MAF failed, diagnosed from bad idle
Fat Boy: P1 30,000 miles - MAF failed quickly, CEL
V45DSM: MY99 37,000 miles - engine blown
Fatman: MY00 50,000 miles - MAF failing so replaced before problems
gatravis: MY99 - 2 MAFs failed but no engine failure (?)
Sonu: MAF changed due to engine hesitating badly
BigMikeyBoy: RB5 WRSport (=MY00 PPP engine-wise) - engine blown due to faulty MAF
BigMikeyBoy again: P1 - engine blown due to faulty MAF
AndyS: MY99 - MAF failed causing rough running; replaced before any damage
SteelX: MAF sensor failed but replaced before engine failed
mutant_matt's_mate: STi5/MY00, 3 MAFs failed in 8000 miles Replaced before damage occurred
Cheesy Puff: replaced MAF and cleared problem with lack of power at higher speeds
Abzdon: MY00 52,000 - replaced MAF before problems occurred
chrome: MY99/00 41,000 - replace MAF after KnockLink showed det problems

+ 5 cases in Holland of this (from EvilBevel)

It seems therefore to be age-related rather than miles, and greatly increased chances of problems with after-market filters and particularly induction kits...

Other bits :

simb: surging on gradual acceleration is common, particularly between 2500 and 3500rpm - seems to be a poor ECU map for the fuelling; should be no need to worry!
WULTK: see above... MY99 and MY00 always surge a bit, particularly between 2500 and 3500rpm

Theo: exactly, I am not scaremongering, just trying to build up an idea of how common it is.

jim_litten: I think I've been driving round for at least 3 months with it like this, maybe up to a year, including on the autobahns... amazing it lasted this long if you ask me!

Scott D: you can either disconnect the battery for a while (e.g. overnight) or do the connector thing. I do the latter, even though it's a bit of a pain. MY00 has two green and two black connectors.

Flat 4x4: couldn't agree more!

Green Scooby: sorry, can't help, don't know much about Dawes or whether this problem occurs on earlier cars - I think not, as so far no-one's said they've had this problem. I assume they changed the sensor between MY98 and MY99.

[Edited to add chrome's entry]

[Edited by Re-Bitten Hero - 12/16/2003 12:24:59 PM]

johnfelstead

The crap MAF's are on MY99/00 only. The earlier MAF's are hot wire and they have a clean routine that burns the oil contamination you get with oiled air filters, they do fail, but no where near as often as the MY99/00 and they are safer to use after market filters with.

The MY99/00 MAF is a thin film type unit, it shouldnt be cleaned, it should be thrown away if contaminated. I think you should avoid using aftermarket filters with this MAF unless you have all the right monitoring tools on the car. I use a genuine STi air filter that flows more than enough air for most aplications, it's not worth increasing the risks to the engine as far as i am concerned.

The MY01 uses a diferent MAF again, this is much stronger than the MY99/00 unit. There have been some failures with this too, but again it seems less prone.

Re-Bitten Hero

Thanks John...


I've now ordered a KnockLink and sensor from BR Developments as they currently have some in stock and Jap Innovations don't. Thanks to both companies for being friendly and helpful .

Cheers
Richard

chrome

johnF- is it possible to use an older MAF unit on a MY99/00 ?
or would it create further problems?
btw- rebitten: you can add me to that list..
My MAF was failing slyly at approx 41K noticed it on the knocklink (select didnt show any MAF error codes) but when I swapped the sensor for a new one all the problems I had had were gone (det, hesitation etc..)

altho my idle on cold start it still a tad erratic (1400rpm as opposed to warm idle of around 600rpm)

[Edited by chrome - 12/16/2003 12:20:33 PM]

johnfelstead

warm idle should be 750rpm, it might be worthwhile taking the idle control valve off and cleaning it and its housing, they get gunged up with oil. If you do an ECU reset it clears the idle control memory so has to go through the setup routine again, the ICV is a stepper motor so takes a bit of time post reset to stableise to the correct location.

you cant use an old MAF in the MY99/00

OllyK

Been having a browse at old threads and the MAF issue seems to be a common one, but it never seems to have a solution, other than fitting a knocklink. From John's post above it doesn't seem possible to fit a pre 99 one or I suspect retro fit a 01+ one.

I have vague recollections that a few people (possibly on a US BBS) did manage to get an alternative sorted under warranty. Does anybody have a solution to the problem or is it really buy a Knocklink or wait for the engine to go bang and hope Subaru will sort it under warranty (and I assume they probably wouldn't??)

ozzy

If the car is under warranty and it does go bang, then they will repair it. As long as it's completely standard, of course.

There's obviously a few cars that have went pop, but what I'd be more interested to hear is how they diagnosed it as the MAF (rather than just taking an educated guess) and what the percentage of failed cars is to those sold. If it's 50 out of 50,000 then the risk isn't that great. IM won't want to publish that sort of data, but the Dealer network must have some idea.

AFAIK, the only methods used to diagnose the MAF would be

a) Select Monitor,
b) DeltaDash,
c) multimeter or
d) fit a new one and hope it sorts things.

I personally don't like spending money when I 'think' something's faulty. Especially, when it turns out not to be it and the feckin Dealer doesn't want the part back

Would it be possible to make an electrical adaptor for the MAF sensor that can display it's voltage (without interfering with it)in-car?

Stefan

ozzy

You don't NEED to fit a Knocklink, just like you don't NEED to run on Optimax or Octance Booster.

The thing is it's beneficial and will help prolong the life of your engine if you do both.

I'm sure other cars (inc. VAG) do go pop due to poor fuelling from things like dodgy MAF's or air filters.

Having said that my Dad's Vectra failed it's MOT due to very high emmissions. I suspected O2 or MAF as he said the economy was ****.

Cost me £150 to find out it was the MAF and get him through the MOT. If I could have stuck it on a meter of some sort and read the voltages, maybe it would have confirmed it for sure without taking a £150 risk.

The O2 sensor was next and at £120, the costs would start to mount up quickly. He did spend £40 for the Dealer to check it over, but they were next to useless.

It's one thing to be paranoid, but I wish we could expend our energies on monitoring solutions instead of guesswork and gut feelings

Stefan

EddScott

My MY00 has 44K and has just had the 45K service.

I get a slight hesitation when the cars cold which goes away after about 5 mins but I just put that down to the engine being cold could that be a MAF prob?. I don't get any other strange things and the RPM on start up is about 1400 which drops to 7-800 odd when warn but doesn't waiver. I also have a de-cat.

I've got a knocklink and boost gauge to monitor things to fit shortly and I've bought a 2nd hand K&N which will be cleaned before I fit it and will go on after I've worked out how to read the KL and whether the KL is set up right.

I'm supposed to be in on the group buy for for the Ecutek re-map at PE and it might be wise to replace certain items before I go but like others on here I don't really want to spend money on something that might be OK.

simb 2

iTrader: (3)

Re-bittenhero - Thanks, when I get it re-mapped this should hopefully be sorted.

simb

EvilBevel

Stefan, very very good second post !

Benji Lad

Are Knocklinks easy to fit for an amateur enthusiast or do they need someone with good, in depth knowledge to fit? (standard MY00 owner who doesn't want his engine to blow.)

Cheers, Benji

Fatman

No mate - very easy indeed. The engine bay part is simple. Remove one bolt, fit sensor and then replace the bolt. Thread the cable through the bulkhead gromet and wire up to the control box. Wiring the power to the control/display box is simple enough; just make sure you have a multimeter/voltmeter to choose the right cables to 'T' into.

There's a good website 'how-to' guide made by a Scoobynetter. Can't think of his name right now, but a search under "knocklink install" should yield it easily enough.

Benji Lad

Cheers Fatman.

Puff The Magic Wagon!

iTrader: (2)

T into the red wire behind cigarette lighter & earth it on one of the screws that holds the gear-linkage cover to the transmission tunnel (directly below the cigarette lighter)

Scott.T

iTrader: (2)

Hesitation when cold is due to the O2/Lambda sensor and not the MAF.

At light throttle/low revs/-Boost the O2 sensor is used to set the AFR. When cold the 02 sensor does not work too well.
It does have a heater element in it to get it up to tempeature quicker, but it's still not quick enough for the first few minutes or so of driving.

You can disconnect the 02 sesnor and it will then use the fuel map. You will notice that this is then smoother when cold.

I done this last week to confirm it was the 02 sensor and it ran really well. After a while you will get a CEL but I ran for 2 days without CEL coming on.

I have heard that using a 4-wire 02 sensor works well as this has a seperate ground rather then using the connection of the 02 sensor to the downpipe as the ground path (I have bought one but not fitted yet).

JColman

I have a MY98 (99 shape) with nearly 70k and have just had the O2 (lambda) and knock sensors fail. These were detected by getting a CEL and then Scoobysport using the diagnostic thingy.
What with two sensors failing and reading these posts I thought I would air on the causious side and have the MAF sensor replaced just in case so rang Scoobysport to get me one but it seems that Subaru got 75 in last week and they are all gone!!!
I think we are all panic buying them!!

sg72

Happened to me.

May 2003.