MOT hydrocarbon & lambda FAIL

[Jwelsh03]

Hello all,

Tok my 1993 Chimaera 4.0 for an MOT about a month ago and it failed on excessive exhaust hydrocarbons and high lambda reading. At the time there was a carbon smell and come smoke under hard acceleration.
I have then replaced all the plugs & leads, stepper motor and MAF sensor.
I have had another test today and has failed again on the same issues.
The car is running very smoothly with little to no smoke.
Any ideas on how to reduce the hydrocarbon and lambda readings?
Thanks

[l10tus]

Did you ever get it sorted?

You know that you have to find a "sympathetic" tester.who understands they left the factory that bad, to be honest I don't believe any Chimx or Griffs would ever REALLY pass a modern test by an unsympathetic tester with only new car experience!

[Sardonicus]

That's rubbish these cars will fly through a cat test if everything is has it should be , the only abnormality is you have to get the main cat up to temp a brisk drive or extended fast idle will sort that, sorry OPer not enough information like gas test result to help

[Loubaruch]

Sardonicus said:

That's rubbish these cars will fly through a cat test if everything is has it should be , the only abnormality is you have to get the main cat up to temp a brisk drive or extended fast idle will sort that, sorry OPer not enough information like gas test result to help

What Sardonicus said. If your TVR still has the CATS intact the emissions should be fine.. My 1996 500 just passed with the testers comment " your emissions are lower than a modern 3 year old car"

[taylormj4]

I wonder how accurate and reliable the analysers are actually. I had one tester failed my car on emissions then he said he'd check the other exhaust pipe and said that was a pass. His conclusion was that the right bank of the V8 must have a problem. I pointed out that the pipes were combined through the centre of the car and then he said he must have had a bad earth on the tail pipe and passed it.