V6 MOT Failure Emissions

[flippa]

got a bit of a nasty shock today. .....my v6 failed its mot on emissions , the garage tried their best to get it passed ,but after a bottle of fuel cleaner? and a 30minute blast up the motorway the reading hardly budged ......the sheet reads LIMITS: 0.30% vol.......my reading 0.70..........second test 0.74 ....they want me to drop it back in tomorrow to take a closer look ....is there anything i can do myself (exept pray) before opening my wallet

[Dolly1]

Hi flippa,
You could try some injector cleaner in the fuel tank,take for a FAST spin.
Only a temporary fix i know,but it might do the job,otherwise injectors out and clean them.

[dandywarhol]

Check the condition of the air filter??

[scanner]

Is that the CO reading or what?

(haven't had a petrol car tested for years so not sure what it is they test for)

[flippa]

Cheers dolly done that Dandy ....air filter ?? its only been in 6 months , i could put a new one in ? i have a few (i read before you say no harm in taking the air filter out for the test?)

Scanner yes tis the CO reading

[scanner]

Scanner yes tis the CO reading

Isn't that controlled by the Lambda wotsit and if that isn't working right the CO goes through the roof.

I seem to remember bro-in-law having that prob with his Escort.

[flippa]

i wont be doing the lambada then are these sensors replaceable ? available ? cheers scanner

[shaun.m]

sounds like the lambda isnt switching you could try taking it out and cleaning it but you would probably be wasting your time they can get clogged try to drive at low speed high revs lock it in first and drive at 30 for a couple of miles to the test station and see if they can test it straight away you never know

[Doone]

Al had this on a V6 - the lamda reading was low and the CO high. The customer didn't want extra expense at that time, so (with his agreement) he unclipped the top of the airbox where the filter sits and it passed.

[flippa]

cheers Shaun, any idea where this is located on the v6 .....not sure these guys are bongo friendly ...and i dont have access to the members area to get a look at the schematics

[Ron Miel]

Is that the CO reading or what?

(haven't had a petrol car tested for years so not sure what it is they test for)

See here: http://www.motester.co.uk/mot-cog.html. Got 10 months until ours is next due, so haven't been carefully through it yet but it looks useful

Good luck. Interested to hear the outcome, ours is a V6 too.

[flippa]

Hi Doone thanks for the info the lambda looks favourite at the moment....should i take the air filter out ? leave the lid off the air filter housing? and also do you have any idea how i can get the correct replacement lambda sensor part no's etc

[shaun.m]

hi flippa not sure of its exact location havent looked at mine , but it will be on the engine side of the cat and will have flexible bunch of wires coming from it dont get it confused with the other sensor which has a hard copper type wire connected

[Doone]

Al just left the lid off at the garage, but there's the possibility of the top sucking itself shut when the engine's revved, so you may prefer to remove the filter. Just don't drive through any lumpy air on the way there. Mazda main dealer will be able to supply replacement parts.

[kawasaki kid]

When the missus old Fiesta failed the MOT on it`s emissions - the lambda was at fault - the tester said to remove the sensor and clean it with brake cleaner as when cars do low annual mileage the sensor gets clogged up with soot - cleaned it up and replaced it and sent it in for a retest and it passed. Just a little tip - dont clean the sensor on a nice clean concrete path - it took about a year for the stain to fade.