New_scooby_04

iTrader: (4)

Hi all,

What are the symptoms of a lamda sensor on its way out? I'm fairly sure my Scooby (std MY99 except for H&S backbox) is running a little lumpy on idle and a bit rich. It's still generally very well behaved, doesn't stutter or stall, no obvious hesitation on boost, but it occassionally gives a little 'cough' on idle and there is quite a strong smell of petrol on start up (more so than I remember). I could be wrong, but it seems a little less agressive on boost too, seem to notice it in 1st and 2nd gear more. That said, I might just not be taking the hoter weather into account!

Shouldn't be the maf, as that was replaced only a few months back.

Any help much appreciated.

NS04

richiewong

Little bit like MAF failure, idle all over the shop and poor ecomony, but thats hard to tell on a scoob

Luckily did an ECU check every other day, one day it would show no fault and occasionally it showed the O2 sensor as being knackered

Just to add the idle problem occured only when the engine was hot and possibly only once or twice per week before the Lambda was replaced.

richiewong

Part No 22690AA321 mucho money from Subaru dealers

Aztec Performance Ltd

iTrader: (234)

When the Lambda sensor has gone, driving off boost is a little rough (closed loop), and idle is lumpy. On boost (open loop) it is uneffected.

Other symptoms would be running rich and fuel consumption being worse than usual.

If you have a Lambdalink you should be able to tell if it has gone.

A cheap universal one will fit.


Bob

catalunya199again

if you need a lamda i have a spare one but i will need to know what wires is on yours as i was sent a wrong one in the post when mine went funny. with the running rich i could smell petrol but my fuel pump regulator was a little high so i knocked it back and it has stopped that

New_scooby_04

iTrader: (4)

Ta Bob -and everyone else- I don't have one at present (was going to leave that and the knocklink to when I get a decat and remap), but I'm guessing that a faulty lamda would show up on a diagnostic fairly easily, so I'll take the car to xtreme and see what they say.

Car doesn't seem rough off boost, but there is deffo the occassion hicup in idle that you can feel as a reverberation though the seat. I'm just very sensitive (paranoid) about my car!

I think fuel consumption is maginally worse, but then this is a scooby we're talking about and if you kept detailed records of fuel consumption it wouldn't be long before you hit the bottle!!

NS04