Im thinking of getting a de cat pipe fitted for a bit more noise and bhp ect question i have is the car i want to fit it to is a uk 1990 mk1 can i leave the cat on for m.o.t. or do i have to replace the cat every year for the test and also when you messure the cat do you messure end of the flange to other end over the cat or across the middle lenght thanks
There’s an article in the June club magazine that covers the emissions test.
Basically pre 92 cars are subject to a non cat test. Presuming the engines in good condition it should pass with or without the cat and the tester shouldn’t have any requirement to check for the presence of a cat.
As for the size requirements I’m sure someone will be along soon who an help with that.
Andy
1990 MX5s use a standard 375mm cat, UK or import. Don’t expect all that much extra pep from being decatted.
When I had my decat pipe put on my first mk1, I also had the timing advanced at the same time. There was a great difference in how it drove.
Whether it was the decat, the timing or both, I can’t be sure…
It’ll be the timing. The factory cat on the mk1 is extremely high flow, good bit of kit really.
Ought to be for the money they want for it, though…ought to be made of gold really.