Car is a '94 WRX with std downpipe and a midsection and tailpipe from an STiV. It passed the MoT last year, but this year failed the fast idle CO emissions.
Readings were 0.4% with lambda 0.990, and 0.51 % with lambda 0.987.
The garage (who also supplied the car 2 yrs ago)suggests it might be the lambda sensor 'choked up', and wants it back tomorrow to 'check it out'.
Does this seem plausible, and if so, can the lambda sensor be cleaned successfully or am I looking at a replacement?

 

If they do want to replace it, insist they use a UK lambda sensor and transfer the wiring over (WRX wires are longer) - works out at half price!

Thanks

Gavin

 

Are you running the car on 95 or97 RON. I know of one instance where the car failed on 95 but would pass on 97RON.

Then again you should be on 97RON anyway because its an import.

Steve

 

Mine also failed last week MY94UK Magnex mid and back with pipercross filter, but on re-test it failed again but he had another go and it passed but he had to get the revs right, last year was the same but the night before re-test I took it for a blast for about 10 miles almost red lining and it passed ok next morning.

 

Yes, I'm running 97RON fuel.
I'll try going for a thrash before I take it in to the garage tomorrow and see if it passes. Are you allowed as many attempts as it takes to pass? The mechanic did say the CO reading was fluctuating a lot and he thought it was going to pass but then it didn't. Maybe one more try would be enough.

 

Hi folks,
My 94 WRX just passed it's last MOT some time ago with a high CO reading, it was right on the limit at 0.5 % . However I suspect it was tested as a UK car which has two cat's whereas my WRX definately only had one in the downpipe, the mid-section which looks like a cat proving to be a resonator.
Does anyone know if
a)the emissions limits for imports are different to UK cars,
and b) if the limits for later cars were more strict ?
Regards,
John

 

They have to test a 94WRX as a standard non-CAT car. They're not allowed to test it as a UK car.

 

My UK95 has passed it's test with no problem and it's only got the front cat in place.

Also can the car pass it's test if the front cat was replaced with a bypass pipe, but putting the centre cat back on for the test.

Just thought if it did it would save a lot of hassle.

 

Steve,
Thanks for the reply. If I remember correctly when they did the MOT test they entered the details into the emissions testing machine and there wasn't an obvious option for an import. Any ideas anybody and are the emissions limits different to UK models?
Cheers,
John

 

When I took my STI for its MOT it was tested as a non cat car as it was not on the listings for the uk , if the car is after june/july 95 then the car requires a cat to pass the emmisions part of the test . Go back and ask them to look at the book or get them to phone the Ministry for confirmation of the regs .
Dave with no cats on his STI v2made in 95

 

Thanks to all who have posted replies.
I took the car for a thrash before returning to the garage for a re-test: got exactly the same result as before, ie CO emissions about 0.4 to 0.5% against an upper limit of 0.3%, so another fail.
The mechanic wirebrushed the lambda sensor and cleaned it with an airline, and then retested: CO emissions now 0.05%, so an easy pass. Cost £30 for labour.
I couldn't convince the garage to test it as a non-cat vehicle -they insisted they had previously checked with the Ministry and it had to be classified as an Impreza Turbo.

 

I had the same a couple of weeks ago with my MY96 UK, failed the emmisions test, CO at about 0.5, the mechanic cleaned the lambda sensor and changed the air filter (which he said was black!!!) and the next test got a 0.00

Stuart