Hi all,

Hope you can help me out, I have a 99 Subaru Impreza Turbo which as developed a fault in that it loses power and hesitates(feels like fuel stavation) between 3,000rpm and 4,000rpm. I’ve just had a service conducted on the car by a non Subaru dealer thinking that it was a dodgy plug causing the problem. However the fault still exists. I’ve tried disconnecting the battery for an hour to reset the ECU but the fault is still there. Before I book the car into a Subaru dealer to find out what the problem may be I thought I would post this here to see if anyone has had something similar on the 99 Turbos or has any ideas on what to try next.

I’ve been offered a cheap replacement ECU from a W reg Impreza Turbo do you think this is worth a try?

Thanks in advance

Cronie

 

This is the problem I have - hesitation and irratic idleing. MY 99. Subaru said the fault is the oxygen sensor.

 

Possibly the MAF (Mass Air Flow) sensor, also called the air flow meter. Notoriously weak on Classic Imprezas. Had exactly the same fault. Cost me £210.00 for the part, plus fitting. Is your "Check Engine" light on? Mine wasn't. If it is, then the emergency running programme will have cut in; it's supposed to prevent the engine revving above 4,000 revs. But lots of other faults can bring on the emergency running programme.

 

At that rev range I'd go with the Lambda sensor, especially if it is under light throttle. If you're finding it under WOT then I'd go with the MAF instead.

Look for pretty crap fuel economy with a failed Lambda.

 

I had something similar when I first had an MY99 I believe it was a boost valve that was replaced under warranty and cured the problem instantly.

I think the main dealer will be able to diagnose fairly quickly for you.

D

 

If it's the MAF pay £75ish for the sensor alone not £210 for the housing as well And do it yourself if you're moderately spanner handy 'cos it's not hard. If you have the problem on WOT (wide open throttle) then it's not the lambda as it's ignored on full beans.

 

Good point, Matt P; Mine had a cracked mounting lug on the housing, so the whole thing had to be replaced.

 

I have an MY00 and suffered the same fault. Problem got gradually worse, until check engine light eventually came on. Turned out to be the MAF sensor. Cost me £146 to have it dealer fitted. They forgot to reset the ECU afterwoods so watch out for this. mazing how some dealers dont understand the tempermental attitude of the EC bloody U.

Rammy

 

You don't want an MY2000 Ecu as they have heir own issues. Plenty of people have swapped these for MY99 Ecu's.
I say, call it a draw and get a Tek3

 

had exactly the same on my my99. 2 mafs later, plugs and leads later and still the same. turned out to be fuel - dealer suggested i try optimax and overnight the problem disappeared, wont use anything else now....

 

had the same, turned out to be a cracked plug and dead MAF, Power engineering sorted mine out when they remapped it but the MAF is well easy to replace, 2 bolts and thats pretty much it!!!! £75 +VAT for the part

 

Had exactly the same on my MY00. It was the Lamba Sensor.

 

Thanks to everyone who gave me advice. The problem did turn out to be the MAF which has now been replaced by Bulldog Subaru in Twyford for £140

The car feels great and again I can't help but grin when I nail the throttle.

Cronie