chocolate_o_brian

iTrader: (22)

i took what i think is the lambda sensor off when fitting a full decat exhaust. the new decat downpipe had a bolt at the top for something but the lambda sensor one on my 95 wrx is smaller and still attached to the old cat.

will my car go boom, as sometimes it idles lumpy and sometimes its fine. could it be idling funny from over or under fuelling.

also could the lumpy idling have something to do with an unpredictable clutch? ie lots of play sometimes...

any help possible would be appreciated.

andy.


p.s. i do plan getting her serviced within the month as shes an import with little history.

chocolate_o_brian

iTrader: (22)

oh if it helps ive kept the old downpipe and taken pictures of what is disconnected... hope ive done nothing stupid...

gaz-cole

are you sure your not getting the cat on fire sensor confused with the lambda on your model the lambda probe should be on the exhaust mainifold on the drivers side of the engine.

gaz-cole

just seen the image leave it disconnected it wont effect anything done the same on mine no probs

chocolate_o_brian

iTrader: (22)

ok cheers mate, thought the pics might help you guys!!!

do you think its the maf maybe then? and sometimes the ecu is trying to compensate. ive tryed the stall method and it does indeed stall when unplugged. so thats a good sign.

andy

chocolate_o_brian

iTrader: (22)

its a mixture lol the car has 93 running gear i think, but maybe a different shell!!! engine is a 93 so was assuming the drivetrain, exhaust etc are, same for that model too???

rossyboy

iTrader: (8)

Your lamda is definitely on the exhaust manifold. If it has gone, the car will be running rich as a safety mechanism and hence mpg reduced.

I didnt notice any change in my idle when it went. In fact I had no idea it wasnt working the first time until MOT and then it wasn't until during a mapping that I found out the second time.

chocolate_o_brian

iTrader: (22)

for someone not quite clued up as im not can you explain where the manifold is please. all i know from putting a full decat on the engine is that the downpipe goes straight to the back of the turbo.

any pics of where the lambda sensor is on a similar age car would be helpful??

andy...

T5OLF

iTrader: (4)

Just the flame sensor leave it unpluged. My lamba is switched using the Apexi hand controller as it was found to be faulty when Andy F mapped it. Been of for a month or so with no probs. I will fix it one day.......

T5OLF

iTrader: (4)

The manifold runs under the engine from left side to right and up to the turbo.

Lamba will be on the right side of manifold. I blocked mine off and put it in the down pipe. If it breaks up it will kill your turbo, in the down pipe it just goes out the exhaust, if it ever breaks up that it.

chocolate_o_brian

iTrader: (22)

just wondering then if its a combination of a dodgy maf or my clutch being on its way out... seems lumpy at idling and also when changing gear...

T5OLF

iTrader: (4)

Clutch won't affect idle, mine plays up some times at idle other times it's fine. Have you reset the ecu after fitting decat? have you checked for any pipes that may have come off and pulling air in? if car stalls when you unplug maf then the maf sounds fine.
Was it lumpy before changing cat pipe?

chocolate_o_brian

iTrader: (22)

i havent reset the ecu no mate, not sure how to do it successfully incase it reveals a fault code and i cant drive it...

pipes coming off, dont think so but hopefully a service from scoobybits will sort this out?

dont think it was lumpy before decating, although maybe once or twice... definatley more of a recent thing though...


if i reset the ecu and say a fault code come up, can i still drive the car. thats why i havent reset the ecu yet. and was gonna leave it.

T5OLF

iTrader: (4)

Yes you still be able to drive car, do a search for ecu reset it's not hard to do.
Resetting ecu and checking for fault codes are different things, neather will stop you from driving.

mike_94_wrx

This is defineately not a lambda sensor, its a cat on fire sensor, wont make any difference if youve not got it connected

chocolate_o_brian

iTrader: (22)

ok cheers mate that seems the vibe im getting...

as for t5olf...

i mat try a ecu reset this week sometime. as long as im able to carry on driving my beloved scoob, im ok for work lol!!! i assumed that when you reset an ecu it automatically check for fault codes and will tell you of any. that is why i was worried if this happened the ecu wouldnt let the car move...

bit stu[id eh? but im relativly new still...