5th Gen Vti - MOT Emission Test Failure

Post by **PreludePete** » Thu Apr 19, 2018 7:20 am

Hi Guys,

99 red top 5th Gen has failed MOT due to :"Exhaust emissions carbon dioxide content at idle excessive" Same problem after 2nd fast idle test.

Can anyone point me in the right direction as to what could be causing the problems?

Pete

Post by **RattyMcClelland** » Thu Apr 19, 2018 9:09 am

Can be a number of things.
Cat, spark plug condition, engine timing, o2 sensor.

If it was me I'd check the plugs first, then replace the o2 sensor or both if you have 2. Then try again.

Post by **vanzep** » Thu Apr 19, 2018 9:48 am

Pete - a local luder had the same issue but had aftermarket exhaust and failed the MOT i think problem was with the catalytic convertor - i loaned him a brand new aftermarket one - it just passed the emissions test and no more

Post by **Merlin** » Thu Apr 19, 2018 10:43 am

Was it a narrow fail or was it by a big margin?

Post by **PreludePete** » Thu Apr 19, 2018 10:53 am

The MOT says "excessive" - 7.3.D.4 for the idle test / 7.3.D.3 for 2nd fast idle test.

How bad is that??

Pete

Jackson Bondy · Post by **Jackson Bondy** » Thu Apr 19, 2018 11:12 am

You should get a separate emissions report attached to the MOT certificate stating the results and limits of the test.

Post by **PreludePete** » Thu Apr 19, 2018 2:06 pm

Garage has said ok now.

They cleaned plugs, checked injectors and put some fuel additive through the system.

Will check read out with MOT when I pick it up.

Thanks to everybody for your input.

Pete

Post by **norks27** » Thu Apr 19, 2018 2:38 pm

Some recommend using this pre MOT to help with emissions.
£12.99 on Amazon.

Post by **vanzep** » Thu Apr 19, 2018 9:27 pm

nice result Pete bet your pleased

Post by **vanzep** » Thu Apr 19, 2018 9:33 pm

norks27 wrote:

Some recommend using this pre MOT to help with emissions.
£12.99 on Amazon.

sure it wouldnt hurt - ive used forte petrol saver once or twice as part of a service but generally id say you dont need to use these cleaners id say use it once every three or four years if its a daily driver and its getting some vtec