T1000

I've been reading posts about the ultra fragile MAF on the MY99 Impreza. It looks like this topic has been done to death before so sorry about a new one

My car has started to idle very low lately, as well as other symptoms such as engine hesitation. Therefore I'm thinking of having a new MAF fitted at my local Subaru dealer as a matter of precaution.

Where abouts is it under the bonnet, I'm guessing it'll be attached to the airbox? What does it look like? Also, I've got a green panel filter, is it worth replacing this for a standard paper element if it's less likely to do damage to the MAF?

Thanks

as355f1

Changing the MAF is a 2 min job, its located on the pipe from your airbox

Tidgy

the bad news is mafs on that year are pretty weak (mine is a 2000 and there ****e as well, which is y i got rid) good news is you normaly get it running funny before when they start to go so it not a engine goes bang before you realise, which it sounds like you'ev spotted, so good work on that.

easy way to check if its the maf is to unplug it while the engines running, if the engine keeps running your maf is fooked, this methos isn't fool proof but a good indication. other option is to get it on a rolling road for a diagnostic run, while it might be the maf sensor you could be chasing a ghost replace a fe parts then find out it was soemthing else all the time, which can end up being an expensive way to do things.

T1000

Thanks for the info guys,
as355f1 - I popped the hood earlier but couldn't find the MAF? I had a look at the air box pipe. Is it hidden away?

Tidgy, yep I've heard all about the fragile MAF on the MY99 - MY00 and it's definitely a cause for concern.I guess the only way round it is to frequently replace.

I actually had a rolling road done a couple of weeks ago and it looked healthy enough. 254bhp and 274 lbft torque. There was a small wavy line on the chart at around 3000rpm which looked od though. They ran the car on diagnostics and it was ok though.

It's coming up for its service soon so I might as well get them to replace it just in case.

Tidgy

its your choice but dont go spendign a fortune trying to hunt a problem.

other option is change the ecu to a mafless system

T1000

sounds good, didn't realise it good be bypassed by an ecu. Does that involve getting the car remapped though?

exvaux

iTrader: (1)

it means a full new standalone ecu like a simtek or apexi with a mafsim which is around 1k fitted and mapped

T1000

ouch, that's a bit more than I was hoping! Nothing comes cheap though. It's a shame this car has an Achilles heel.

Does this also count for Sti and p1 models?

Also, please could someone tell me where the MAF is in relation to the airbox, can't find it at all

xX Domino Xx

have a look here

http://i264.photobucket.com/albums/i...filterview.jpg

might not be in exactly the same position but they mostly look the same

richiewong

On your intake pipe just after the airbox before the bendy convoluted pipe.

All MY99/00 MAF's are the same whether UK or JDM.
Part No 22794AA010
And you'll need a T20 secure torx bit to remove it or a normal T20 torx if you simply sanp out the centre pins

Your's is different from the one pictured but in the same area on the back of the pipe.