fat_boy

iTrader: (1)

hi all i just brought me a new maf sensor as my old one had failed and gave me the maf sensor code with the two plugs under the dash so i have just fitted it and reset the ecu how JGM tells you to and drove it steady for 10 mins and the check engine light was flashing once every second which indicates all is well.
But lol there had to be one the car is fine when your just driving steady and drives perfect but as soon as you put your foot down it pops bangs and you can feel it hold back so i was wondering if any of you brainy people out there have any ideas as i have no ecu fault codes and it only does it when you try to go flat out
pls help as this is really getting me down as i have waited 3 months to buy a new maf and now my car still dont work

cheers

Splitpin

Would help if you'd told us what year and type of car you have, and what the state of tune is.

Also, was the new sensor you've bought brand new still in packet and purchased from a Subaru dealer, or a used/pre-owned one? Are you sure it's the correct part for your car?

When you say it misbehaves as soon as you put your foot down, do you mean it won't handle any boost at all, or will spool up fine and then starts to "hold back"?

fat_boy

iTrader: (1)

sorry its a 97 jdm sti ver 3
the only thing on it is a 3" blitz nur spec r and a mushroom filter other than tht its standard the maf is second hand but was working fine when i took it off another scoob yesterday.
its also an orange maf the same as what was on it before.
it starts to spool up fine then it hold back and popps etc at about 5000k-6000k
hope that helps?

fat_boy

iTrader: (1)

please help there must be some1????

Splitpin

There are limits to what we can do via the power of the interwebs - all we can do is make educated guesses, and unfortunately we don't have much to go on here.

There are any number of causes for what you're experiencing, and the use of a secondhand sensor is a big random factor. You really want this in front of someone who can diagnose the car properly.

bob r

iTrader: (46)

Any abnormal whooshing sounds?

Possible boost leak

fat_boy

iTrader: (1)

nope i ust know before i put the new maf sensor on i couldnt even drive it down the road really it just back fired and held back really bad but when i put the second hand 1 on it drove ok and was fine untill you booted it the it poped and banged but the engine light was on before and reading maf sensor prob but now theres no light and no fault???
so im abit stumped
Am i right in saying that when i changed the maf and reset the ecu the car should be completly fine straight off or do i need to take it a good STEADY run to blow away 3 months worth of cobwebs? lol
cheers

bob r

iTrader: (46)

When I had a maff issue it was purely a case of erratic idling and I kept it completely off boost until a new one was fitted. A new one was fitted and car ran as it should.

Sound like you could have 2 problems and the change of MAFF partially sorted the problems. Coil packs all ok?

Did you disconnect the battery to reset the ECU?

The car won't need any cobwebs blowing away. There is obviously another issue. Try PM ing JGM he is very helpful on these matters.

fat_boy

iTrader: (1)

ok will do many thanks
took it out for a short steady drive and realised its only running on 3 so checked coil pack and thats ok so now going to fit some spark plugs and see if that sorts it if not then i will get some new ht leads but any ideas if that dont work as to what it could then be???
cheers

fat_boy

iTrader: (1)

bump

madscoob

iTrader: (3)

fit new plugs and regap to 0.6mm also as the mods you have done i would fit ngkbpfr7s and not 6s 6s cane have the spark almost blown out at high boost , thats what i was told anyhow i fitted them and it cured mine . while ure at it chech the o2sensor when they start to go they can show code 34 maff as well as thier own code

fat_boy

iTrader: (1)

hey guys finally just got round to changing plugs and its sorted the prob so thankyou for all ur help
cheers Ben