RON

Will the car still run?
Would it run rich all the time?
Would I get no reading on my AFR?


I have just fitted the AFR, getting no reading at-all, but no cel either!!
HELP!!!!!!!!!!!

my00 uk, decat etc!

Dark Blue Mark

1)YES
2)Some of the time - Off boost it uses the lambda from memory, and they normally fail rich.
3)Maybe - depends on the scale of the Dawes AFR I guess. Not sure if it goes from 0v or not. I think it would have to be completely dead to do that?

The CEL will normally come on if its completely twatted, but not always from what ive seen.

Ahh, the joys of modding.

MB

[Edited by Dark Blue Mark - 12/9/2003 2:46:21 PM]

Andy H STi

Just wondering myself.

My CEL comes on in the hire gears when I'm accelerating hard. On tickover it also runs really rich and from behind there is a strong smell of unburnt fuel, this also creates a sooty deposit on the rear.

Going for a full remap in the new year.

This from what I read on various posts points to a knackered Lambda sensor?

Is this right? The car is a V5 STi Coupe

CHeers guys

Andy

greasemonkey

Could be Andy, but if you have a CEL coming on, follow the instructions here about putting the ECU in read memory mode. At least then you'll know what the cause is, no guessing necessary.

Ron, to add to Mark's comment about question 2, the ECU uses the lambda input to control the fuelling when the car's in closed loop mode (i.e. off-boost). When lambda sensors start to fail they do normally under-read, and so the ECU will attempt to bring the reading up to where it thinks it should be by adding more fuel, hence the car running rich off-boost, and the fuel economy being carp whether you're booting it or not.

If you can't see any lights at all on the Dawes, it could simply be that the sensor's so far gone that its output is too low to light the first light. Have you tried sticking a digital voltmeter on the wire to see if there's anything coming out?

[Edited by greasemonkey - 12/9/2003 3:44:58 PM]

Dark Blue Mark

They should pay you on here GM

MB

RON

Did an ecu reset, got error code 32, so o2's knackered, trying to source one as I type, trouble is, there's no main dealer for bloomin miles!!!
Does anyone know a main dealer that does parts by mail???


Ron.

ps, thanks for all the help!

Dark Blue Mark

Power Engineering or Xtreme Scoobies. Think Xtreme will be cheaper. Both will probably be better than the dealer.

Good to get it sorted

MB

RON

Waiting for mail back from both of them!!
Cheers!

Quoted 120 in dorchester, but that was from someone else getting it from Subaru!

wigan wayne

Mines gone over the last couple of weeks.

With the decat I can even here the extra fuel poping in the
exhaust!
I tried a universal one from Halfords but is sending wrong voltages
and is fueling even more than the knackerd one. 9 miles to gallon- plodding

The worst bit is car is early MY93 which uses a specific sensor
£300 buma.

I've also been advised to check the oil when fixed, as some fuel can get into the oil which isn't good.In extreme cases you can smell it in the oil (apparently).

WW

RON

Halfrauds couldn't help me, didn't seem to know what I was on about!!!!!!!!!!!!
Mine pops all the time, sounds great, but I think it's costing me a fortune!!!
Just got mail from Knowlesy, between 120 and 150+vat!!!

wigan wayne

Ron

The part is L300 3 wire zirconia £25
I've got one spare in 10 days time if you want to try
before you buy- cheap.
It may work on the newer cars not sure.

WW

RON

WW, thanks for the offer, gonna get the original part, seeing as it controls fuelling, I see as quite important!

Ron.

wigan wayne

No probs.

glen4

RON
I've got one you could try, it gave a CEL on my first car but none of the symptoms, you're welcome to give it a go if you wanna come pick it up, it's still in the box so has the relevant part number etc, Cheam motors are pretty good for parts by post, but speak to me first as I need a D/P gasket

RON

Glen, are you on days or nights??

glen4

I'm off at the mo, RON, but on a course tomorrow and pi55 up on thursday lunch time, give us a call

johnfelstead

if the Lambda sensor is buggered (sounds like it) unplug it from the loom and run it disconected until you can get a new one installed. The ECU is designed to compensate for this and gives a set reading for lambda that will improve your on cruise and idle fuelling. Your engine will run much smoother and could save you a fortune on fuel doing this.

The_Judge

RON,

I'm glad my branch of Halfords isn't the only bunch of ****...

RON

JF,
Thanks for your input, thankfully I don't actually need to use the car until I get a new Lambda, ringing Cheam motors in a minute!!

Ta

wigan wayne

John

If you unplug the lambda do you get a cell and car
goes into safe mode?,
As I could do with doing this as I have to wait another week to get mine
and it's fueling like mad.

ww

greasemonkey

Some people get a CEL Wayne, some don't. The engine won't go into limp-home mode; as John says, it'll substitute a fixed value for the lambda when it would otherwise be running closed loop.

Don't forget it runs open loop when you're on boost anyway, so under these circumstances the lack of the sensor is no loss.

Dark Blue Mark

Has anyone passed an MOT with the 02 disconnected?

MB

jgevers

Idle and part throttle are regulated by lambda.
The 3 wire sensors should switch between approx. 200mV and 800mV at something like 1 Hz. on the signal wire. If the signal increases to over 1 volt it normally means that insufficient earth is obtained through the exhaust. This would make the engine run slightly leaner on idle and part throttle. In this case the easiest route forward is to fit a 4 wire sensor and pull the grey wire direct to earth. The other two wires are for the lambda heater. Check for heater operation by measuring the resistance (6-18 ohms)and make sure that 12V supply and heater earth is present.

regards,

Job