Hi there
was wondering if anyone could help. My classic wagon 99 has just failed it's mot on emissions. The guy told me it's most likely down to the fact that I have a ss cat back system. Is this true that by getting rid of the centre section cat the emissions fail the test? I was told by hayward and scott that I would be ok with just the forward cat but the fail seems too coincidntal.
Anyone know the answer

prob. gonna have to buy an old centre section and chuck it on for mot
emissions are as follows
CO2=1.489- fail
HC=76ppm- pass
Lambda=.0951- fail
So lambda is low and the co2 is way too high. does this sound like the sensor or the cat?
Cheers
Grant

 

had a similar problem and the mechanic reved the car at about 3000 revs for around ten minutes got the cat really hot and it just pasted the second time around hope this helps

 

My my99 passes with just a 100 cell sports cat in the downpipe.

 

cheers for the reply mate

 

Yeah, you should be okay with just the downpipe cat.

As mentioned, take the car for a hoon for 10-15mins using plenty of boost/load to 'ignite' the cat. This normally gats the CO2 reading right down - typically into the 1/100s of % , not mere 1/10s of %.

Just hope they can get the Lambda reading between Lambda 0.97 and Lambda 1.03 on the machine...

If after doing that the CO2 is still too high after the 2nd fast idle test, then suspect the Lambda sensor and/or one, or upto all, of the coilpacks too. You can check the Lambda sensor is cycling it's output voltage correctly by using a multimeter or voltmeter - enter 'lambda'. 'lamda' or 'o2' in the search facility to find out how to...