HI guys!

I have a problem with my 97 sti when it gets hot the idle becomes very rough jumping up and down and almost stalling now if i disconnect the lambda and run it the car idles fine(maybe a little slow) but consistent!

Now I went to my local parts place and they sold me a lucus universal lambda and fitted it, but the problem has come back, I disconnect it again and it's fine!!

Any ideas? Do I need to buy a Subaru one or do you think they maybe something else wrong?

Also where is the best place to get one? can you get them online? as there are no Subaru dealers near me?

Last question Sorry Is it ok to drive with the lambda disconnected?

Thanks Phil

 

If it didn't come terminated with a connector, then did you wire the new one up properly?

The two wires that are the same colour (both black?) are the heater "+" and "-" so don't matter which way you wire them to the loom's heater wires. The other different coloured wire (white?) is the actual signal wire which outputs a voltage to the ECU.

You can voltage test both sensors using a multimeter...

Jam a paperclip into the connector for the signal wire... touch the paperclip with the multimeter's "+" red probe, whilst grounding the "-" black probe to the inlet manifold. With the car up to temp and idling steadily, the Lambda's voltage should repeatedly cycle between 0.1 and 0.9V.

If you run with a non-working O2 sensor, fuel cons. will go up in normal off-boost driving; plugs will possibly soot up prematurely(?); and you may end up knackering the cat (not sure about that?). Come MOT time, it most certainly won't pass - the CO (and prob HC) will be through the roof.

 

its not the lamba sensor mate its the airflow sensor on the air box have u put a cone filter on it or something when u do this the air flow sensor goes it then sends incorrect readings to the mixture and then the lamba picks up on this

 

Yes, despite my ramblings, I agree with the above. Bound to the MAF.

 

cheers guys I defo wired it up correctly, also i brought another maf from a fellow scoobynet member, tried that and still has the same problem! could that be duff aswell? i have also cleaned them one at a time as they were dirty but still no difference!!
the votage on the maf is around 1.1 - 1.2v on tick over with lambda disconnected

I could try the lambda, but when i plug it in the idle is all over the place so it will be hard to read!

Has anyone got a orange label maf, local that i could pop over and try i'm in Halstead Essex

 

Try buying a oe lambda sensor from subaru or who ever sells them. Cheap lambda sensors can fail very quickly. Would be surprised if its the maff on a 97,, 99/00 play up as i have found out on a few occasions..

 

Yep, that's spot on for idle - so sort of rules that out.

 

Cheapo universal lambdas do not pay mate, i went through 3 in as many months, 2 of them lasted under 100 miles. Got the Bosch one from Just Lambda for UK lambda sensor sales and all has been fine since (famous last words)



Spot the difference, even the wiring is better quality

 

Yeah, and when mine couldn't get through emissions last Aug, I stumped up for a Subaru OEM spec one... about £270 IIRC!

 

I too have just bought a Bosch O2 sensor from Subaru. Cost £150 plus VAT. I'm sure you could get one cheaper but I needed it for the MOT.

 

Cheers guys so it looks like i will get another lambda then!!

 

sorry me again b13BAT did you get the bosch uni lambda LS02 or did you get the just lambda own lambda sensor with the plug on 250-23088

i know the bosch 1 is cheaper but which is better?

 

I got the LS02 mate, came with a good length of wire and a connection block, can recommend

 

is there anything which could cause lambda senser to go