Hi all I'm new to this site I have 1995 skoda Felicia and it has failed the MOT on emissions and was wondering if any one could tell me if cata clean stuff would work to reduce the emissions or would it be best to buy a new lambda sensor any help would be great.

To give any kind of decent answer, we'd need the figures from the MOT failure - there can be many things wrong, and knowing the figures helps massively.

To give any kind of decent answer, we'd need the figures from the MOT failure - there can be many things wrong, and knowing the figures helps massively.

mine failed last year too . got a new cat off fle bay £50 . passed easy on retest

Yeah, but that doesn't mean to say that's what's wrong here. Many a person has bought a new cat to find that it's made no odds.

i agree with darren on this, we need to see the actual figures to give you some sort of idea on the cause/cure.

here is the figures for the MOT : fast idle test 2543 rpm co 0.22% , hc 65ppm , lambda 1.10 natural idle test 1000rpm co 35%

here is the figures for the MOT : fast idle test 2543 rpm co 0.22% , hc 65ppm , lambda 1.10 natural idle test 1000rpm co 35%

i scanned mine and it came up lambada probe , changed that failed again . new cat bingo

natural idle test 1000rpm co 35%

you sure that's not 3.5%???

yeah it was 3.5% it was a typo error so it would be the cat i need to change

that lambda reading is a little high to be honest, but not miles out... from those results i would say it's simply a case of the cat not being hot enough.. you've passed the CO test at fast idle and failed it on idle

IO'd agree; if you have access to a genuine "while you wait MOT" place, take the car for a fast run for 20 minutes (up and down a duall carriageway is fine) to get the engine and cat properly hot, then get them to leave it running whilst they do the test.