Hi folks,

Anyone fitted a new MAF on a Version 5?
I bought a MAF from my local dealer, fitted it the other day and the "Check engine" light stayed on, let it tick over for a min, no change, fitted the old one back in, light went off. Does the ECU have to be reset when fitting a new one or should it change over with no annoying lights?

Cheers in advance

 

Light should go out when the new one is fitted mate,if the maf is the only problem of coarse.This happened to me recently and as soon as a put the new maf on the light went out,make sure its the maf and only the maf thats throwing up the cel.

 

I swapped my maf on the P1....V5/V6 and the light didn't go out.

I had to do an ecu reset, then it went out. You have to clear the fault from the ECU.

 

Thanks for the replys,

The "check engine" light wasnt on with the original MAF - but on fitting the new one it made the light come on, iam thinking now it could be a faulty MAF from Subaru?
The reason I was changing it was because there was bit of a splutter in 4th/5th gear at around 5000rpm when driving hard, but usually only happens once, then its clears and its usually fine after that.
Iam a bit confused (nothing new there)

 

You should reset the ECU after changing any sensor to clear any corrections learned from the a faulty one, but, even that said, Bo is incorrect (and WhiteWagonMan is correct) - the CEL should go off immediately when the new sensor is fitted. If it doesn't, as you suggest, likeliest reason is that, as you suspect, the new sensor is faulty. This does very occasionally happen - especially if the sensor has been thrown around a bit. Did the white box it came in show signs of damage?

The only way to be certain about what's causing the splutter is to datalog the car and see what's happening to the various sensor inputs and control outputs when it occurs. Otherwise it's a process of elimination.

Take the new airflow sensor back, get it swapped and reset the ECU after fitting, and then see where you are.

 

Thanks for the replys everyone -
Splitpin - tried taking the MAF back today which was much fun, I have to go back tomorrow to have a mechanic fit it and read the fault code with a super duper machine that cost £8000, I did say to the bloke, dont expect me to fork out any money for this testing of the faulty Subaru part. So i will see how I get on with that.
The splutter is strange, its in higher gears, 4th and 5th, when the boost is full on, it pulls really hard but then starts to flutter a bit, but the power then comes back, usuallly after that it may happen a couple of times then seems to run ok. When it first happened after a bit of inspection the bottom intercooler hoses was leaking slightly (just a slight bit of deposits at the clip on the hose) tightened it up and seemed to be fine after that, but it returned a few days later. The flutter/splutter dosent flag the "CEL" though.

 

Hi again, whats the Datalog thing?

 

For f**k's sake, you've been bull****ted. You don't need any machinery, let alone 8 grand's worth, to read the fault codes on an original shape Impreza. All you need to do is connect two black plugs under the dash and read the fault codes off the check engine light. Have a search on here for "black plugs" or look for the article on Scoobypedia that tells you how to do it. Do it before you go back to the idiot tomorrow and surprise him with your knowledge.

As above, if you find the fault code yourself, the dealer won't be able to charge you for doing so, will they?

Even better, if you go out and do it now, and tell us what fault code(s) are stored in the ECU, we'll be able to give you even more ammunition to take with you.

Incidentally, what model of car do you have? An STi version 5 (or an import WRX), or a UK specification MY99 Impreza Turbo 2000?

Datalogging means plugging his "£8k diagnostic machine", or a £200 laptop PC and some software, into your car and driving it around a bit.

 

I would do that just now but iam working night shift and didnt take my car to work - I'll do that in the morning - They said they need to prove the part is faulty, i said well test it with a test meter, but he just looked at me and said Subaru wouldnt accept that test (ha ha, seriously), (i didnt know if that would actually work) - they have another in stock, so, he said when the fault code established is the MAF then it will be replaced, however, if the fault code points to something else, then I will be charged, thats when i said i wont be paying him anything for the pleasure of proving that the part they sold me was faulty. I knew he was bumbling a load of rubbish.
What is the code for the MAF?
My motor is a import, 1998 WRX RA LTD

 

All he'll do then is say that "computer says no" and that the MAF is okay [conveniently gets him out of that one] and... "Oh dear, you need X, Y or Z..." [scam completed]... whilst you'd be left even more out of pocket and still with a rough runner.

Don't give him the pleasure - do as SP says, and check yourself. Straightforward enough to do...

 

Thanks for all your help guys,
I checked the code before I went back to Subaru, code 23 = MAF.

Arrived at Subaru on Tuesday morning and a rather stressed out mechanic came out after 10mins and plugged the laptop in, I told him at this point the faulty MAF(sold by Subaru) was in its box and that it was the original MAF that was in the car, he said "well i cant check it unless its fitted" i said the code is stored in the ECU and its code 23 - he then fumbled around and said, "ok, that my bit done, code 23 it is."
i went back to the parts desk and the guy I had been dealing with said, thats fine we can go ahead with the warrenty claim,, come back on Thursday,, knowing that they had it in stock i asked why he couldnt swap it over, he said its was the way Subaru did things. he said we can post it, but i suggested posting a MAF wouldnt be a good idea as they can be fragile. he didnt seem to care that i would have another 60 round trip to come back and get it and basically said "too bad" at the inconvienence. I then paid for another brand new MAF and they would refund me the money on Thursday..
Went home disgruntled - called Subaru dealer on Thursday at around 12, the receptionst, said the guy i needed to speak to was out and wont be in till 4pm, but on further investigation she said there is a problem with the claim etc and i wont get refunded till the following week,, quickly got the number for warrenty dept in head office, called them explained what happened, quoted a consumers goods act thingy, he called be back within 10mins, and said the Subaru dealer is talking mince and should have changed that part as soon as I came back to the garage, no messing around with codes and laptops etc, he said he had called the dealer to explain that they were in the wrong and to refund me ASAP.
Fitted the new MAF - all sorted including the misfire.
Thanks again for your help - hopes this helps someone else.

 

Fantastic (in the end, anyways).

Nice one