Newbie needs MOT help please
 

Hi guys, I need some help please...

Just taken my 94' WRX import for mot. It failed on one thing. Emissions.

The printout reads

CO: <3.50%vol
8.47%vol Fail
HC: < 1200ppm vol
327ppm Pass
Idle speed: Pass
Smoke level: Pass

Exhaust emissions carbon monoxide content after 2nd fast idle excessive (7.3.D.2b)

The car has no cat. Which the tester said wasn't normally a problem as he has passed de cat imports before.
The issue as far as I can see is that the Lambda sensor has been chopped off. Is this normal when cars have been fettled a bit? Or has someone buggered it up somewhere? Will reconnecting the Lamba cure my problem? If so, where does it connect?

Any help on this issue is really appreciated

car should of had a non cat test:-as if its a wrx there is no exact match in database
the limit of 3.5% is correct but the tester has chosen the wrong description in the mot computer as it should say excessive carbon monoxide content at IDLE

lambda sensor wont make any difference as far as idle but unless you are running a aftermarket ecu and its been temporarily swiched off it needs sorting straight away,

the lambda is in the exhaust manifold mate, the part that has been chopped if is probably the cat on fire sensor (which you dont need) lambda will make a difference to idle and low load fueling if its faulty

ah i see. The bit that has been chopped is about a foot or so behind the turbo

the tester tried doing a basic emissions test and it was to high for that. What I want to know really is how to get the emessions to a passable level

erm that may be lambda then, in the early cars they should be in the exhaust manifold and not in the downpipe, not that it matters really. Have a look in the exhaust manifold and see if its there

faulty lambda could well be your problem

What air filter you running?

high CO is usually either a blocked air filter\induction blockage or a lambda sensor failure!!!

Its got a HKS induction kit on it

Not that then!!

I have been known to tie a £10 note to the de-cat pipe with welding wire so it can only be seen from underneath,

Never had a problem with emissions since!!!!

:Suspiciou

Thanks for all the constructive comments so far.
I've had a look tonight, and my lambda sensor is in the manifold and wired up. So the question is how do I know if it's faulty? Can it be tested?
On another note. Removal and inspection of the cone part of the HKS induction kit revealed it's rather grubby and falling apart. Where can I get a replacement?
Thanks again guys