MOT failure - emissions

[misterdroid]

Bit of advice from the experts required......

My 182 failed the MOT on emissions last week, the CO reading was 0.57, all other readings are ok.
The tester advised me that the lambda sensors might need changing, so £240 later took it for a retest and the reading was exactly the same. Bugger.

I had a sports cat and stainless system fitted 18 months ago, so I started to suspect this was faulty, but the exhaust fitters (long life) tell me that the cat, which is only on a 1 year warranty, may have been ruined by the car. So i need to get a new one fitted, another £200.

My problem now is, assuming it passes the MOT retest on Friday, what can I do to avoid needing to put a new cat in the car every 18 months? Could it be a dodgy remap by a previous owner?

Can anyone advise an expert I can turn to in the South London area?

BTW I haven't noticed excessive smoke or fuel consumption, and it runs perfectly.

 

[1958steveflying]

If it is the cat, decat it after the mot and just put it on each year for it's mot.

 

[JamesBryan]

£240 later!

What did you have done to it?

 

[misterdroid]

Lambda sensors are £110 each, there's 2 of them plus fitting.

 

[VR46-G@Z]

Just out of interest in the 18 months you've had the cat on have you had a missfire of any sort which needed a plug change or anything? Because this can damage a cat and cause poor emissions...

 

[M26]

Was the car properly warmed up before it was tested?

You've had your pants pulled right down there ! Why would you change both sensors at the same time anyway? Not to mention a good diagnostic session would tell you if they were working properly or not !

 

[Amos91]

If its the cat, just get a second hand genuine one off here?

 

[Ethan1996]

Chuck some redex in it, heard that can do some good with emissions but never tried it myself!

 

[Adam D]

Arn't the standard cats on these decent 'sport' cats anyway?