+4 failed MOT on emissions

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Mike Hughes
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+4 failed MOT on emissions

Post by Mike Hughes »

My +4 road car just failed the MOT due to emissions. It has massive CO and HC levels and is clearly running very rich. With the standard ECU having no adjustment I assume it must be a sensor driven situation. I've replaced the pre-CAT lambda, but it's not that; any of you clever people got any ideas?
All help welcome....
Cheers
Mike
Mike Hughes
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Philip Tisdall
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Location: Warwickshire

Re: +4 failed MOT on emissions

Post by Philip Tisdall »

Mike,
It is a problem I had with my +4. All I can suggest is that you give the car a really good run so the exhaust system is really hot when they test it and try and avoid letting it tick over before the test. I use a garage that tests a lot of “old” cars and they know the issues that these cars have. So maybe go to a garage that is use to testing these cars.
Philip
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Mike Hughes
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Re: +4 failed MOT on emissions

Post by Mike Hughes »

Thanks Phil,
I managed to fix it today, it turned out to be the EVAP valve being stuck open, it was causing the emissions and rough idle.
It passed the retest at a CO of 0.004.
Thanks for your interest.
Cheers
Mike
Mike Hughes
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