MOT failure - Emissions
Discussion
Hi, advice needed before my retest!
My 1995 1.8 MX5 failed on excessive CO during fast idle emission test.
HC and O2 are ok (as was CO during the natural idle test!?)
Car had an o2 sensor 2 yrs ago and a new cat in 2006 when i bought her from a dealer. The car only does 2000-3000miles/year during the summer and is parked up over winter. so wouldn't have thought the cat was 'worn out' or could little mileage & infrequent use shorten it's life?
Garage have tried to get a pass and allegedly tried 3 times (inc after giving her a blast round the block to ensure the cat was hot) but can't diagnose the problem, simply suggesting i replace cat/engine temp sensor or O2 sensor.
Anyone advise me before i buy a cat off ebay to see if that fixes it!!!?
My 1995 1.8 MX5 failed on excessive CO during fast idle emission test.
HC and O2 are ok (as was CO during the natural idle test!?)
Car had an o2 sensor 2 yrs ago and a new cat in 2006 when i bought her from a dealer. The car only does 2000-3000miles/year during the summer and is parked up over winter. so wouldn't have thought the cat was 'worn out' or could little mileage & infrequent use shorten it's life?
Garage have tried to get a pass and allegedly tried 3 times (inc after giving her a blast round the block to ensure the cat was hot) but can't diagnose the problem, simply suggesting i replace cat/engine temp sensor or O2 sensor.
Anyone advise me before i buy a cat off ebay to see if that fixes it!!!?
How hot did they get it / how far did they drive to warm it up?
Mine failed on emissions last year but after giving it a 20 minute thrashing the emissions levels had come right down and it passed easily. It needs to be fully hot all the way through, not just have the water up to temp.
Mine failed on emissions last year but after giving it a 20 minute thrashing the emissions levels had come right down and it passed easily. It needs to be fully hot all the way through, not just have the water up to temp.
If the lambda reading on the printout was within limits then that suggests the lambda sensor is working OK.
Most aftermarket catalytic convertors have far far less precious metal compound in them, and don't last as long as the original. What is your engine like for oil consumption, any oil which is being burned can clog up and eventually kill the cat.
It could be worth tipping a bottle of cat cleaner into the petrol tank and making sure the car is driven nice and hard for a few days. Its only £10-15 per bottle and is worth a go. It got my car through, last time.
Most aftermarket catalytic convertors have far far less precious metal compound in them, and don't last as long as the original. What is your engine like for oil consumption, any oil which is being burned can clog up and eventually kill the cat.
It could be worth tipping a bottle of cat cleaner into the petrol tank and making sure the car is driven nice and hard for a few days. Its only £10-15 per bottle and is worth a go. It got my car through, last time.
My 95 1.8 struggled before eventually scraping through. The tester commented that in his experience many Mazdas of that age took some coaxing to pass. In my case I'd taken it for a drive beforehand to warm it up but not as far or as fast as I'd have liked because I discovered at the last moment that the rear fog had packed up and it took a few minutes to persuade it back into life! In future I'll make sure the engine is properly hot.
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