Liam_J_Kelk   10 #1 Posted April 19, 2015 Good evening.  My wifes car has failed its MOT on the fuel emissions. I have changed the back box as it had a hole in and also the cat section.  It is still failing on emissions.  Does the cat need to be run in? Is there anything else i should be looking at doing?  Car is an X Reg 1.1 Clio Grande  Thanks Share this post Link to post Share on other sites Share this content via...
geared   299 #2 Posted April 19, 2015 Do you give it a good Italian tune-up before it go's in for the test?  Have you read any fault codes, could be something like the engine temp sensor. Share this post Link to post Share on other sites Share this content via...
mafya   238 #3 Posted April 19, 2015 Have a read of this= http://www.pistonheads.com/gassing/topic.asp?h=0&t=805866&mid=0&nmt=Major+MOT+emissions+failure! It also states what needs to be looked at Share this post Link to post Share on other sites Share this content via...
boringal   10 #4 Posted April 21, 2015 Good evening. My wifes car has failed its MOT on the fuel emissions. I have changed the back box as it had a hole in and also the cat section.  It is still failing on emissions.  Does the cat need to be run in? Is there anything else i should be looking at doing?  Car is an X Reg 1.1 Clio Grande  Thanks  try changing the lamda sensor, its positioned on the exhaust just behind the cat Share this post Link to post Share on other sites Share this content via...
bossdogg   10 #5 Posted April 21, 2015 Put some engine cleaner in called forte never fails Share this post Link to post Share on other sites Share this content via...
Dardandec   32 #6 Posted April 21, 2015 Post the readings on here and we'll have a better chance of advising you.  A blowing exhaust can cause a high lambda reading but you have sorted that. High HC is unburnt fuel so a possible misfire and high CO could be a faulty cat, but you've replaced that. Also a blocked air filter and dirty oil can cause high CO.  When was the last time it had an oil and filter and air filter?  And no a catalytic converter doesn't have to be run in. Share this post Link to post Share on other sites Share this content via...
mafya   238 #7 Posted April 21, 2015 Put some engine cleaner in called forte never fails  I use Forte fuel system treatment every service in my van and car, its top stuff! Share this post Link to post Share on other sites Share this content via...