This might be similar to another thread. I have a 1996 W140 Shape S Class. its a 320, which is popular here in the UK.

Mine has repeatedly failed the MoT on emissions. Ive changed tha Lambda senor, spark plugs and leads.

The problem is that during the emissions test the C0 levels dropsbut the lambda reading rises.The garage says its the CAt, but im not sure.

Is there only one Lambda senoron thisd model (in the Y of the exhaust before it divides in 2 ??

I also sprayed some injection cleaner into the air filter.....had this contaminated other senors ??

Any help would be appreciated. Thanks

 

Ive scolled down thought the threads...and come across "MAF senor". What is this, and could it affect the emissions ??

Nev