My car is a Turbo 2000 MY00 - standard apart from bailey dv...

The car has developed a very slight pop from the exhaust when changing gear (clutch flat on floor) from 1st - 2nd - 3rd (not driving hard) and i have noticed quite a lot of black soot in the exhaust (more than normal)

so i had the spark plugs changed to see if that helped and all was fine and she was running great - idled perfeclty but the pop backfire noise was still there.

....then i get home from the garage and the car stalled as i came to a stop.

i started her back up and found that when idling the revs keep dipping right down to 200 then going back up to normal (900 i think), the revs keep doing this and sometimes it stalls the car. its difficult because when i approach a junction where i have to stop the car almost stalls

i have been told that the most likely cause is a faulty MAF sensor. i've ordered a new one. but my question is could this faulty MAF sensor cause the backfire i was talking about + running too rich etc?

 

I'd say yes, as a guess. The MAF gives the ECU an approximation of the air available to allow correct fuelling, so an incorrect signal could result in too much fuel for the available air, although lean running is more common. Classic MAF symptoms are an erratic idle and a flat spot in the power delivery around 4k revs. 98-00 cars were prone to MAF failure, but either a DIY ECU reset, or a diagnostic monitor should isolate it easily. Make sure you have ordered just the MAF sensor, and not the MAF & housing combined, as there is a massive price difference. MAF alone should be IRO £90.

 

yer i ordered one from scoobyworld (£90 or there abouts). do i need to reset the ecu once i fitted the new MAF? if so how do i do that?

and is it ok to drive (very gently) until the new MAF arrives? many thanks

 

Scoobypedia | Trusted knowledge for everything Subaru | Knowledge / ECU Reset

Scoobypedia | Trusted knowledge for everything Subaru | Knowledge / Reading ECU Fault Codes

Reseting it now should bring up an error code (CEL light flashes) which will confirm where the fault lies. I'd guess an ECU reset after fitting the new MAF would also be wise.

 

could be a BOV venting to atmosphere causing it to back fire also

 

Also worth checking the lambda sensor as well as the MAF if running rich and popping throught the exhaust.

 

I have the exact idle problem you mentioned above bar the popping.
Stalls sometimes when clutch is depressed toward junctions.
Its been to 2 main dealers countless times and no fault has been found
Its was also suggested that it was my driving style, which really p!ssed me off. my04 wrx.

 

Let us know how you get on mate.

 

Try unplugging the Lambda sensor ( on downpipe just after turbo ) and driving the car before you unpack the MAF and can't return it.
Kevin