Emmissions

1. Docbooze Infrequent Poster Joined: Jul 2010 Posts: 170

   #1 21st October 2010, 18:57

   Car failed the MOT on emmissions , passed on everything except CO at more or less double. Just changed the fuel/air filter and an oil change before the MOT.
   Would new plugs and a dose of redex plus a good thrash make a difference or am I looking at a new Cat with that sort of CO reading.
   
   Appreciate any advice.
   
   Cheers
2. pepper953 Established Member Joined: Dec 2006 Posts: 1280

   #2 21st October 2010, 20:33

   hold revs at 3500 till cat gets real hot then have it tested
   a good 5 mins
3. burgerfeet Infrequent Poster Joined: Oct 2010 Bridgend Posts: 231 VTS 2002 - well the Mrs does

   #3 21st October 2010, 22:57

   Your cat has had it. The best way to 'light' a cat up, and it sometimes recovers it by burning excess carbon out of it is to....
   
   ....2nd gear at 30mph. Hold the brake to maintain the speed at the same time as then putting your foot to the floor, wide open throttle. This gets the cat much hotter than just holding up the engine rpm at standstill.
   
   It obviously heats the brakes up so do it on a nice straight road. Only have to do it for no more than a quarter mile.
   
   Do it just before the MOT and see what happens.
4. burgerfeet Infrequent Poster Joined: Oct 2010 Bridgend Posts: 231 VTS 2002 - well the Mrs does

   #4 21st October 2010, 22:57

   this assumes that the lambda reading was good of course.
5. Docbooze Infrequent Poster Joined: Jul 2010 Posts: 170

   #5 21st October 2010, 23:28

   Cheers for replies. Emissions part of the MOT is a nightmare. Dont wanna have to retest it if it fails again as I'll proberly have to pay some sort of fee and need the car asap for work so might just bite the bullet and get a £50 Cat for the MOT and fit it myself.
6. brosnan Established Member Joined: May 2008 Kent Posts: 1127 BMW X5 4.4 PETROL

   #6 22nd October 2010, 00:27

   Both worth a go before spending out on cat ^^^^
7. burgerfeet Infrequent Poster Joined: Oct 2010 Bridgend Posts: 231 VTS 2002 - well the Mrs does

   #7 22nd October 2010, 07:34

   Quote:

   Originally Posted by Docbooze Cheers for replies. Emissions part of the MOT is a nightmare. Dont wanna have to retest it if it fails again as I'll proberly have to pay some sort of fee and need the car asap for work so might just bite the bullet and get a £50 Cat for the MOT and fit it myself.

   You will probably end up going that way in the end. Don't forget to initialise the cat when you have fitted it or it won't work properly. The cat should come with first run instructions.
8. Nik_L Saxperience Forum Bum Joined: Oct 2010 Here and there. Posts: 3372 205 GTi

   #8 22nd October 2010, 07:58

   Everytime ive had a car fail on emissions i sling in a bottle of Redex and go kick its cunt for a few miles.Always seems to do the trick.
9. Dan-Jnr Infrequent Poster Joined: Mar 2008 Manchester Posts: 164

   #9 22nd October 2010, 10:15

   Emissions tests are annoying. I have to bang on my standard exhaust everytime.
   Try the redex trick, or find another exhaust with cat.
10. Docbooze Infrequent Poster Joined: Jul 2010 Posts: 170

    #10 22nd October 2010, 10:21

    Quote:

    Originally Posted by burgerfeet You will probably end up going that way in the end. Don't forget to initialise the cat when you have fitted it or it won't work properly. The cat should come with first run instructions.

    Cheers for replies. Gonna try the redex route and see if it will scrape through , if not I'll just get a cheap CAT of Ebay and throw it on for the test.
    
    What is the procedure for initialising a CAT ? Do you have to run them in gently or something ?
11. burgerfeet Infrequent Poster Joined: Oct 2010 Bridgend Posts: 231 VTS 2002 - well the Mrs does

    #11 22nd October 2010, 11:19

    It depends on the cat manufacturer but it could be such thing as straight after fitting, not driving, hold the engine rpm constant at 2000rpm for 10 or so minutes. It will be in the instructions.