Cats - Gavin
How old does a car have to be for it to be legal to remove the catalytic converter and have it replaced with a straight through pipe?

My car is a 92 J plate and is having some exhaust problems. News cats are expensive.....

Re: Cats - John Slaughter

There's been a thread on this before, but I think if the car's pre'73 you can remove the cat. Someone will no doubt correct me if I'm wrong!

However, you'll only get the full benefit if you get the ECU reprogrammed to suit the non-cat exhaust system of the car, which will have lower back pressure. Although the mixture requirements will be somewhat different, I believe you need to leave the lamba sensor in place, as the ECU is expecting an input there.


Apologies - of course it's '93! - John Slaughter
Yes - '93 of course - Sorry!


Re: Cats - Gavin
Thats good.

I should be able to save a few pounds on a shiny new exhaust system if I can lose the cat.

My environental conscience will have to suffer, and I will use my bike more for short trips.

Thanks for the answers.
Re: Cats - Michael
93 methinks!
Re: Cats - honest john
No. If the car is a 92K or later and was originally fitted with a cat you can't remove it. Any car up to the end of 92J you can. What happened after August 1992 was that there were a lot of leftover non-cat cars, so they were given a cat immunity. Then a few manufacturers failed to supply the data for the cat testing software, so immunities were exteneded right up to the the enf of 95M. All cars registered after that date have to pass a default test even if there is no specific testing data for them in the MOT computer.

Re: Cats - Gavin
My car is a 92 J plate Saab 9000, so following your argument I can remove the Cat and live happily ever after without emission fines :)
Re: Cats - Peter Todd
I used to own a 1990 Volvo 340 with a Cat fitted, I was advised by the MOT tester that if a Cat was original equipment then irrespective of build year a CAT was needed for the MOT. Although some exhaust suppliers did disagree with this statement. Thankfully I never had the need to find out the truth.

As an afterthought, if you are having the tracking checked on a car with power steering is it advisable to keep the engine running? Any comments.
Re: Cats - Andrew Hamilton
Even better with a 1983 Metro - no catalyst, no expensive ECU. Simple, easy to work on, and only a 4.5% CO limit to pass at MOT.
Metro????? - David Lacey
In a sense you are right Andrew, but on the other hand, who wants to drive an '83 Metro? ;-)



Value my car