brett1990

have a annoying problem the car is hesitating from 3500-5000 rpm somtimes intermittently the cel comes on and off the odd time but sometimes for quite a while
I did a code read on it with the 2 black connectors and got codes
12 starter signal
21 engine coolant temp sensor
22 knock sensor
31 throttle position sensor

I also did a read with just the green connected and it will intemittently flash 22 for the knock sensor

Also there is a recipt from subaru diagnosing the same problem but tracing the fault to the maf

What do i go with :/ has anybody had the same issue or can help me out! Cheers

ade_sti

iTrader: (2)

Did they change MAF or have you as I would - first thing I would do on a 99 plate turbo.

brett1990

Yes they did the recipts show its had a few in the past i cannot remember the date it had it but i dont think it was recent, also it makes no difference to the car what fuel is in it and why would it put a knock code up for a maf or is it a subaru thing? Also the maf is the removable type not the full unit with the varing stickers

keljon

iTrader: (10)

Given the fault codes, I would say in order of probability
Knock sensor
Coolant temp sensor
MAF (check if yours is the modified one with a green dot of paint)
Lambda (recently had an issue with the plug on mine which didn't log a fault code)
Plug Leads

Have you cleared the fault codes to see which ones return?

keljon

iTrader: (10)

If the maf is faulty, the engine will run lean and knock hence the fault code, TBH if you aren't sure it's been replaced recently, I would replace it anyway to be on the safe side, faulty mafs have killed plenty of these engines

keljon

iTrader: (10)

Also if the modified one (green spot of paint) is fitted then its prob worth trying to clean it first, halfords do a £5 can of electrical cleaner for this purpose

brett1990

My maf is the one where you can remove the sensor from the housing with 2 t25 trx screws
i didnt clear the codes no i just read with the black then just the green while driving, i could drive 5-10 mile with no code but the hesitation still there but on the other hand after 100 yard, it also seems to be at ita worst after i have drove like a grandad for a little while starting to hestitate at a lower rpm range

thunder8

iTrader: (1)

i would do the knock senser cost about £30 if it still does it then the maf at £125

Pong

iTrader: (2)

wait, so, if i replace my knock sensor and the the maf is faulty (even if it's not coming up when doing fault check), will it damage the knock sensor, or will it just bring error code back? dont want to damage my knock sensor again if thats the case..

brett1990

http://item.mobileweb.ebay.co.uk/vie...id=13742542130

My maf is the same as this but there is quite a few different ones?

keljon

iTrader: (10)

You won't damage the new knock sensor, if its detecting knock because the maf is faulty then it's doing its job. I have a good used maf sensor if you need it £35 posted

Pong

iTrader: (2)

thanks, i will change my knock sensor sat/sun and will let you know

brett1990

Let me know how it goes i take it you have the same issue as me? Going to order a maf from ebay

Pong

iTrader: (2)

Well changed knock sensor and after ecu reset i have no error codes!

keljon

iTrader: (10)

Don't bother with the eBay mafs, they are a waste of money

keljon

iTrader: (10)

Sweet

brett1990

changed knock sensor, removed bleed valve, new plugs pfr7b still the same bought a maf off ebay before seeing the post for do not buy one of ebay haha and it must be the wrong one as the filaments look different inside and it cuts out with it on, cross referenced the part no for it befor i bought it with one from a recipt i have from subaru for one and went off that as there were no numbers on the old on. so im still in the same predicament and money down the pan, oh and no more cel after replacing the knock sensor the old plugs i removed looked quite lean mainly on no 1 & 3

brett1990

Seems to be doing it mainly under heavy load in 4th and 5th and very bad when there is a few ppl in the car and going uphill, it seems as if its running out of fuel and it pops back through the inlet and sends the boost guage through the roof! Also after piping the stardard boosr controll up the boost is up and down like a yo yo right the way through the rev range, puddleing my brains now :-$

brett1990

Changed coilpack still the same just waiting on local subaru to get me a maf

brett1990

Another thing aswell will the maf need rescaling due to the aps wing mount and is it a full map job or not? been looking at getting it re mapped but the figures are out of price range at the moment

brett1990

seem to have sorted the hesitation with a earth strap from the inlet mainifold next to the coil pack to the shocker top mounting bolts.....somthing as simple as that?