markpm

Ok Im having trouble with the idle speed on the car and have read this can sometimes be due to a failing MAF sensor.
Heard they can be got hold of for £75-80?

How easy are they to fit? Is it just a screwdriver and plugin job?
Is it easy to get to? (car is a 99 STi Type RA)

Fatman

Yeah, that price sounds about right. It's a doddle to change. Remove the electrical plug, the sensor is held in by 3 (?) bolts. Swap-out/swap-in, bolts back in and you're done. AFAIK, yes, poor idle can be symptomatic of a failing MAF sensor.

markpm

Cheers Fatman!

Sorry for the denseness! but where actually is it?!
I have the standard airbox on the car. Think its somewhere around there?
Might have a look tomorrow and see if I can find it etc...

Fatman

It's just after the black plastic airbox. After the airbox, the inlet pipe becomes circular in profile. The MAF is in that first 'round' section. You can't miss it - there should be no other electrical-type items plugged into the inlet pipe. The sensor is pretty much vertically mounted, so the plug sticks upwards.

markpm

Cool!

Thanks a lot for the info, I'll check it out tomorrow...

zhastaph

The sensor is horizontal on that model and points rewards towards the turbo. Find the air box, and it is litterally an inch or 2 to the right of it. Though as Fatman says it is the only electrical connector round that area so you cannot miss it.

I just wanted to add, I got exactly the same car (great aren't they ), I've been having trouble with eratic idle on mine after a good thrashing. I've changed the MAF, it was defo fooked cos the knocklink lit up light a christmas tree when you floored it. But the idle problem is still there, I'm also finding that at low revs (up to 3,000) she is very lumpy. I'm putting both of these problems down to the Lambda. I should be fitting this tomorrow, so if you're still having probs with yours after you've changed the MAF, then stick up a post and I'll tell you how I got on.

Fatman

Ah... I think you might have a point about the sensor orientation! OK, I retract the "vertical" comment. Mine's vertical, but then again I don't have the airbox any longer.

zhastaph

Just seen this;

I'm guessing that means you don't have one yet?

Couple of points that may help;

• If you try to get one from Subaru it is exactly the same MAF as the one fitted to the UK MY99 and MY00 Turbo 2000's and don't let them tell you otherwise. Quite understandably they're not keen on supplying spares for imports, and so will probably give you the "that's only for uk models" line.
• If you have a friend with a 99/00 model it is worth trying one, as it is litterally a 2 minute job to swap over.
• If you are in any doubt at all about the MAF, replace it, they are only 70 quid and they will destroy engines when they are faulty. Have a look in the connector (MAF side) when you take it off, if it has 5 metal contacts then it is an original so replace it. If it has only 4 then it has probably been changed, but unless you get it checked or you have a KL fitted or you know it's been replaced recently then suspect it also.
• Oh, and be careful when you take the screws out, they have a nasty habit of falling irretrievably down into the engine area some place

markpm

Cheers zhastaph!

Where can they be bought from?
I'd have to go mail order as Im on the IOM and theres no Subaru dealer over here.

Any ideas?

Cheers
Mark...

zhastaph

I'm on an Island too, same prob

I phoned the nearest Subaru dealer who posted it to me for a fiver