Dark Blue Mark

Right,

MY94 WRX
Scoobysport backbox
Scooby ECU
Forge VTA (soon to come off)

Fast idle

Co
Limits <0.3%
Actual 6.05% Fail
HC
Limits <200ppm
Actual 150ppm Pass
Lambda
Limits 0.97-1.03
Actual
0.823 Fail

Natural Idle
Co
Limits <0.5
Actual 2.01% Fail

My thoughts are that the CAT may have failed, or more likey the Lambda or MAF sensor has gone. It does hunt a tiny bit at idle, which suggests the MAF / Lambda. Advice please?!

Taking all the mods off before I sell the car, and before re-test.

MB

scoobyboy

lambda sensor

Dark Blue Mark

That would cover the low Lambda reading - Would it also explain the massive CO reading?

MB

scoobyboy

yes because it controls the fuel mixture via reading the amount of oxygen in exhast gasses to much it richens it up to little it weakens it off

Dark Blue Mark

Cheers,

Will let you know if it works.

MB

Dark Blue Mark

Ok, where does the sensor live?

I could find it blindfolded on my MY99, but a bit more tricky on the WRX.

Presume its on the DP somewhere?

MB

Pete Croney

Hi Mark

I agree with Scoobyboy that it will be the lambda sensor. A CO reading above 3% is a sure sign that its failed.

Dark Blue Mark

Thanks both,

Pete,

Do you sell them or is it better to go for a Halfords job? Might be selling the car soon so don't neccasarily want the Rolls Royce option! If they realy are bad then ill go for the pukka option.

MB

Charlie H

The sensor on an early wrx is in the header pipe just inside of the drivers front wheel and an import one has a longer lead than the uk ones so it's not a straight swap. Universal ones can be made to fit AFAIK but I've never done it so maybe someone else can point you in the right direction.

Dark Blue Mark

Thanks for that Charlie, just need to source one now.

MB

Nowucme

DBM /Anyone, can you tell me where the Lambda sensor is on a MY00 and how easy it is to replace it?

Cheers

Robin

stevem2k

It's on the downpipe just after the turbo on the MY00

Steve

Dark Blue Mark

Yep,

Its on the top of the downpipe.

Stand in line with the steering wheel and look for the silver heatshield covering the turbo, at the back. If you peer down there, you can see the downpipe feeding off the turbo. The Lambda will be sticking out on the downward section, pointing towards the intercooler. Easy to remove, just need the right size shifter / spanner on there. You need to disconnect the plug from it first.

Lot blody easier to change than a WRX

MB

Nowucme

OK, slightly confused (apologies)!

I had a TSL d/p put on just under a year ago - i.e. no CATs.....is the sensor actually on the d/p or is it on the turbo? How big is it to look at?

Dark Blue Mark

Its on the Dp just down from the turbo. Its about 5 or 6cm sticking out at right angles from the DP. Has a while connector on it and the sensor itself is threaded in.

MB

Dark Blue Mark

http://stefanostadal.homedns.org/step1_a.jpg

See there. Its the white plug on the far left of the pic. That leads to the 02 sensor.

MB

Nowucme

OK, Cheers - just went out for a peek and can see it clearly.

What are the options on getting a new one?

Thanks for your help - much appreciated....

Dark Blue Mark

Expensive.. try power Engineering or Subaru Dealer. You can get them from Halfords, but not sure thats a godd idea personally.

Graham goode racing do them. All well over £150 I think.

MB