Has anyone heard of there being any problems with Pipercross panel filters, as in damaging MAF sensor, forgive my ignorance but what does this sensor do and how does it become damaged?Thanks.

 

The MAF (or mass air flow) sensor is of supreme importance to turbocharged Impreza engines. Its job is to measure the amount of air going into the engine, something the ECU needs to know accurately in order to calculate the correct fuel mixture when the car is running under boost.

If the sensor under-reads, the ECU won't inject enough fuel into the cylinders, resulting in the engine running lean, which in turn leads to high cylinder temperatures, detonation, and engine damage.

MAF sensors wear out even under normal circumstances. However, their death can be accelerated if you use a filter that simply doesn't work well enough (allowing the fragile sensor element to be hit by dirt and dust particles travelling at high speed). If you use a filter that is covered in large quantities of oil, or a similar sticky particle-trapping media, the sensor can be damaged both by the filter media coating and shielding the sensor, or by burning off on it.

Don't have any experience of the Pipercross filters. Hopefully someone will chip in with an informed opinion. However, if you've not bought one yet, you're probably better off going for one of the "known good" designs; i.e. the standard Subaru paper filter, the freer flowing STi one, or the K&N or Green alternatives.

 

The oil in the filter gets onto the wire and damages it AFAIK. Apparently the Green filter is the one to get for the standard airbox.

 

Ooops. Greasemonkey's post wasn't there when I replied.

 

ONLY if the filter / induction element has been over-oiled. If the element has been cleaned and has no oil on it then the opposite is true and it lets through dust and dirt which has the same effect in blowing your maf.

I ran a MY00 on a K&N - no problems as long as the filter is taken care of as per instructions: Clean every 30K miles and then lightly oil using K&N filter oil.

I haven't run a pipercross although I have heard horror stories.... I have however heard horror stories for every sort of filter. IMHO - look after the filter and it will look after you.

Rich

 

The filter is fitted to my 99 turbo and has been on the car for about 3000 miles it runs fine but on reading another thread I realised I may be doing some damage I will replace the original tomorrow. Thanks for the advice.

 

ITG filters user since 3 years and absolutely nothing wrong with the MAF sensor.

 

get a lambda link, another gauge to keep an eye on

Sure it reads lambda which is the rear O2 sensor, but thats a measure of how rich/lean you're running.

 

the most fragile MAF is used on the MY99/00. Dont use an oiled filter with this MAF sensor. The best filter to use if retaining the air box is the genuine STi filter.

 

I've had an ITG on the car for a while and its dropping crap everywhere, maf died once but I noticed it on the meters, seems to be ok now, going for sti one next.

 

I had a ITG to.....when car was in at PE have a TEK2 done noticed a large amount of oil in the housing of the filter,,,,,,the kind lads there cleaned it up and fitted a K&N for me

 

I use an ITG on MY00 - I just make sure I do a monthly inspection of the air box (only takes a couple of minutes). I did have some goop on the inside of the airbox when first fitted but this was not MAF side. Have noticed little amounts of residue oil which I clean up but all in all seems to be o.k. I also remove the MAF compartment and check the hot wire and the inside of the housing for traces of oil - up to now no problem....the ITG has been fitted for about 2K miles.

HTH