As mentioned the maf cartridges are definately the same for JDM and Eurospec cars afaik, regarding the state of the maf .... there is no way that they will know if its ok, all they can do is see that the select monitor doesn't report a fault, the engine isn't running so they have no idea how it is reacting under any sort of revs or load, insist its changed ... what price that against another new engine. Part no is 22680AA310 for the new age cars according to my pink parts book and is as stated for EJ205 and EJ207 engines. Should be about £70 ish as well.

cheers

 

John you are wrong the late small turbo YB does use an airflow meter. These dont go bang if you fit a replacement panel filter. Maybe it is you who is showing your ignorance not me.

Clearly if the part you refer to is so susceptible to contamination LOL oil in this case ( not that there is much of that in an engine )it is not really fit for its purpose. If your definition of modified is a direct replacement panel filter(which is legally not a modification) then i don't know what the world is coming too maybe you should get a job working for the Subaru warranty declines dept.
Do Evo's go bang if you fit a direct replacement air filter ? Or perhaps it is something to do with the p155 poor design of a subaru engine component.

[Edited by co55ie - 12/17/2002 8:39:26 PM]

 

For sale 1 ITG filter "as new"


Cheers for all the advice guys.




[Edited by Andy W - 12/18/2002 7:49:32 AM]

 

Must say I sort of agree.An ITG panel filter and a backbox are not really major mods.I fully understand that anything that damages the MAF is a disaster,but there have been 7s going bang with the standard filter,and did Aaron Birds have an aftermarket filter?
I'm not saying it is,but poor design needs to be considered.
PS I think thats 5 STI7s I know of having major engine failures in the UK all with under 5k miles and no major mods.

 

OK, I know this isn't a MAF-related post, but can someone explain in scientific terms why you can't tell if a MAF is 100% A OK?

AFAIK, the MAF's in the later cars 99+ measure a voltage change as air passes over them. If you can read the voltage, then why doesn't this indicate if it's OK or not?

It won't tell you if the air is poorly filtered whether you're running a OEM paper filter or an oiled-filed one, unless you can detect contamination after the filter.

Unless someone can give a scientific or tested result it all sounds like speculation. Not disagreeing with anyone, just very confused.

Are all cars this badly monitored. In theory, my car running std OEM paper filter could have a duff MAF, which may not be detected by the ECU and coz my engine to go bang. Having an ITG filter will (allegedly) increase the risk (by what percentage?), but it sounds to my uneducated brain as poor design?

Stefan

[Edited by ozzy - 12/18/2002 1:02:37 AM]

 

I hope that your dealer got you a decent courtesy car for all of this!!!!!!!!!!!!!!!!!!!

 

Haven't heard of any Justy's going bang, so maybe best to stick with that as a courtesy car

 

co55ie and John - you're both half right.

YB engines didn't have MAF measurement at first - but when they swapped to EEC4 EMS they had an MAF meter - IIRC this was at the switch from sapphire to escort.

I'd agree with John on mods - different air filter and exhaust are modifications, which have been done to increase engine performance. (otherwise why bother apart from noise)

This has to effect engine durability. In effect you're moving from a setup which has been subject to durability testing by the menufacturer and been through some kind of sign off process, to one which hasn't. The OEM is quite within their rights to refuse a warranty claim based on this.

N

 

Ozzy, the worry as I see it is if the MAF sensor fails gradually it can under-read on full load leading to a lean and advanced situation (detonation). If it fails properly and triggers a check engine light then the engine is much safer as the fault is recognised and it goes into a safer limp home mode.

The old ECUs seem quite good at sorting out knock if the car is running normally. With an under-reading MAF sensor they seem to just ignore the detonation - maybe they only control in a certain range. A MY99 car I logged was audibly detting and under-reading on the MAF on full load substantially - the ECU was none the wiser, well it was pulling a few degrees out but it was clearly not enough when you heatsoaked the car.

Since STi 7s are detting at high boost with decats and letting it through so that you can hear it, and apparently not correcting it, then the new ECUs are arguably no safer.

I am coming around to the idea that every Subaru should have a Knocklink!

[Edited by john banks - 12/18/2002 10:07:25 AM]

 

Thanks John, so there is a way of monitoring the situation. People seem to comment all the time on the damage a duff MAF can cause (which is a good thing), but fail to tell anyone how it happens and what steps you should take to monitor the car properly if you do change something that may (or may not) decrease it's reliablility.

Stefan

 

NDT fitting a direct replacement panel filter such as a K&N is not legally deemed a modification, it is absolutely no different to fitting a champion or halfords own brand one. Unless Subaru provide you with these filters free of charge which they don't then you are entitled to fit which ever brand you choose without affecting the warranty in anyway. That is the law of the land and Subaru are obliged to comply with this.

 

This debate isnt about the legality or otherwise of an aftermarket filter, this is about how to prevent engine failures due to MAF contamination. If you care to read all the info, you will see that the MAF was replaced on the newer cars by a less robust but more acurate sensor, the earlier sensors are less prone to failure. The most likely reason for this change is down to emisions regulations getting tighter, which is after the cossie went out of production.

I had forgoten about the T25 turbo escort cossie, no one does any serious tuning with those because you cant get much more than 270BHP out of them without it becoming very expensive with turbo and ECU swaps. All the cossies prior to the last run of small turbo escort cosworths dont use a MAF sensor, including the Escort Cosworth with the P8 ECU.

 

No 2 piston for me

 

JohnBanks,

I have an Apexi Turbo Timer with the auxilary mixture display hooked up to the OEM lambda sensor. On light throttle cruising and at idle, it usu reads between 14.4 and 14.7. With progressively more and more throttle opening, this figure drops steadily, showing mid 11's at half throttle and dipping into the 10's with WOT.

I know this lambda sensor is a narrow band item and the ECU only uses it for closed loop control at cruise and at idle, but would you say that if it is showing such figures (even with a narrow band sensor) at WOT almost certainly means that the car isn't running lean?

Cheers!

 

Sounds perfect... IF the sensor is accurate. There are two lambda sensors on the WRX - one before the uppipe cat (pseudo-wideband it is only accurate down to low 11s:1 AFR), one after, not sure about the STi (since no uppipe cat) - does it only have one? If this is a narrowband, then the figures are useful to know as very approximate guidance.

 

co55ie, until bloc exemption (referring to servicing) gets abolished then the OEM does have the right to void a warranty unless the vehicle has been fitted with normal service parts by a approved dealer.

A K&N air filter is clearly not a normal service part.
If you fit a high flow air filter you are increasing air mass flow (or else what's the point?) and therefore engine performance - which has an impact on durability.

That's relatively minor compared to the fact that you are also introducing additional failure modes - e.g. the fact that MAF sensors seem to fail on Imprezas with non-standard filters.

 

Cheers John, I'm pretty sure that the MY01 JDM STI RA only has 1 lambda sensor, and thats after the downpipe cat (the JDM cars only have this cat). I have never seen any other IIRC and I have no idea whether it is wideband or narrow band - I'd be surprised if it is wideband.

Since this car doesn't have to meet the strigent Euro emissions as a type, this lambda sensor is probably there only to give some form of running economy at cruise. I'm guessing that once the throttle starts opening up, all the control goes open loop.

But my point is - assuming the lambda sensor is functioning properly and is giving me 10-odd figures with WOT, do you think that it is reasonably safe to assume that there are no "lean mixture MAF issues"?

Cheers.

 

NDT you are wrong you don't even have to have your car serviced by Subaru as long as you can prove that it has been serviced according their guidlines. Very hard for Subaru to prove otherwise.

With regard to the the filters a K&N will surpass any standards and requirements set by the manufacturer in this case Subaru so will not effeect the warranty in anyway.

The air filter has absolutely nothing to do with the rotten design of the mentioned MAF sensor. This part alone would cause the fault as it clearly is not fit for its purpose.

If fitting a direct replacement air filter and a backbox can cause the engine to go bang then to be quite honest the engine design must be at fault in the first place. Subaru should not market a domestic car that is running on a knife edge as far as its thresholds go. There really is not alot anyone can say to defend this if they are being honest.

 

RT yes as I say they sound fine, but if it is a narrowband, they are only a very rough guide.

 

But K&N panel filters are oiled which could in theory be deemed to cause MAF failure through oil contamination.

 

The problem is the MAF sensor which is clearly tempremental and susceptible to contamination. If the K&N panel filter exceeds all of the manufacturers criteria which it does then Subaru as a manufacturer do not have any case to argue, as the fault is with the sensor and not the air filter.
That is the law in the UK. It really is of little consequence what the YTS Service Manager at you r local garage says, ask for the explanation in writing you will never get one as this would give you grounds to sue.

[Edited by co55ie - 12/18/2002 6:11:59 PM]

 

meanwhile you sit at home waiting for your blown up engine to be rebuilt. Get real Co55ie. If you can prevent a failure, why not do that? You are being an **** for the sake of being an ****, there is no issue with the guy not having his car repaired under waranty, so please shut up about that.

 

Co55ie,

Subaru use paper filters (no oil). The K&N filters are oiled. I'm sure even you can see the difference here. We know that the oil can contaminate the MAF and therefore lead to lean running. I would presume it is for this reason that Subaru use paper. Therefore I would also assume that the engine was designed to work with a paper filter. If you introduce an oiled filter then you are introducing an element that is outside of the scope of the engine design. This is not a difficult concept to grasp, I can only presume you are pursuing this for the wind up?

It is fair enough to replace a part that is equal or an improvement on the original part. But this would mean you have to use a paper filter of better quality NOT an oiled filter.

I'll leave it at that because I know you get your kicks from stirring people, personally I'm not bothered but I'm sure plenty of other people will bite just to keep you happy

 

John I am not being an **** you are. I clearly stated that a replacement filter would not invalidate any warranty. So what is your point ?
John shouldn't you be designing F1 cars for McClaren they need to play catch up and a man of your vast knowledge would obviously be able to get them back at the front of the grid, but I would try learning to read first as it may help.

 

my point is quite simple. This discusion is not about the legality or otherwsie of an aftermarket filter, can you not get that into your thick skull?

The waranty is not being questioned, so stop going on about it as though it is, you are ruining a technical discusion.

 

'you are ruining a technical discusion'

Yes, a recurring theme in all posts made by Co55ie.

D.

 

LOL! DJB

Johnfelstead, (thats Mr to you co55ie ) We all know you are right on this one, it is well known what a dud MAF sensor can do, I've lost an engine myself which was attributed to this....my fault, running a blitz induction system,looks and sounds great however a better description would be:
..."ineffective shiny tin box oily rag filter"... utter rubbish on our cars IMHO.
Why people monkey around with their air filters when there is
a Almost zero power gains
b The Potential for disaster which is now well documented.
is totally beyond me. I think after market tuners of any merit should avoid recommending them.

Co55ie you are great for wind ups! , and know more than you at first reveal on many subjects however please dont fudge the worthy advice on offer here for the sport M8 it could prove expensive for some poor blighter later.
I actually agree with you that it is a real shame the Subaru sensor is so prone to contamination, I am sure if there were a less prone sensor available with the same accurate output it would have been fitted, in the mean time using standard paper filters and replacing the sensor cartridge every 20,000 miles or so seems a very sensible suggestion.

[Edited by scoobycar60 - 12/18/2002 10:34:13 PM]

 

Cheers JohnB. I also thought that it was reasonable to assume such.

 

worth a read. http://www.scoobynet.co.uk/bbs/threa...hreadID=159955

 

I was looking forward to a good old fashioned flame war!
Cosie - you can do better than that, even with your meagre position on this issue.

Si