What do these do please guys and what can affect them ?

Cheers
Scud

 

The MAF sensor sits directly in the intake air flow stream for the engine. On an Impreza this is located directly after the air filter. It's purpose is to convert the volume of air flow into a voltage that the Engine Control Unit (ECU) can use to calculate engine load. This is necessary to work out the air/fuel mixture and when this mixture should be ignited within the cylinder.

Criss

 

So by changing the exhaust to a 3inch bore might possibly send this a bit of course ?
Reason i ask is i've taken the BOV of my car cos i thought it was causing the car to loose boost but the car still feels the same.
I dont know if it cos i have got used to the car or theres something wrong,i suspect theres something wrong,its not pulling like it was when i had it.

Scud

 

What is the year and bhp of your car and what mods have you done ?

I'm not 100% sure but the full 3" system may not be suitable, you need to be running big power for one.... 2.1/2" may be needed, all according to what you are running though.

The MAF is a delicate area be carefull with that for sure, have you an induction kit fitted ? or standard air box ?

 

As said the MAF (Mass Air Flow) senoser measures the intake air.

No the exhaust won't effect the MAF sensor, putting an induction kit on can effect the accruacy of the MAF and can also cause it to fail. Can't see the 3" exhaust causing a problem, especially as you still have your Catted downpipe, mine ran a full 3" exhaust with standard downpipe (with the standard turbo and intercooler) for quite a long time and found the car rev'd easier and more freely with the 3" than it did with a 2.5"

Have you got a boost gauge so you can see if you are actually losing boost??

 

The car is a MY98,as for bhp i would of thought it was standard.

The induction kit was on the car when i bought it and was running great.
Since i've put the nur spec on and changed it to optimax it doesnt seem like its running as quick, also some times theres a hesitation or feels like.

I thought it might have been the BOV so ive taken that off but still no tidy power ( unless ive just got used to it )

No theres no boost gauge on there either Dean.

Ta
Scud

 

Should i do the test thing on the MAF,disconnect while the engine is ruuning see if it stalls ? or reset the ECU

 

exhaust size on a turbo car doesn't matter cos they don't rely on back pressure like on non turbo cars, on a turbo car the faster you can get rid of the gases the better so 3" will be better flowing than the 2.5"

 

Just tried out the MAF test and the car stalled so i guess thats working.

Now im stumped,any ideas guys

 

if you a in a pickle with the maf i got an sti one over here . it might be faulty under pressure

 

Would you fancy having a spin in my car lom, just to see what you think bud.

Cheers

 

no prob fella see if she is up there . can do

 

Whenever is good for you Lom

 

as long as its after 6 pm every thing is fine fella pm we can sort it out