with or w/out cat

[mirage]

hi,im swaping my m40 for a m20b25.is the any difference if i replace the cat with a not cat earlier type exhause....will this effect performance or consuption?

[ric325i]

cats cause restriction. they strangle the flow slighty so if you can bin it, bin it. but remember if you engine is after 1991 (i think - im saying that lots today) then to pass an mot you will need the cat in.

[mirage]

thanks r the advice but some are telling me ill loose some low end torque and idle problems.....is this true?

[Brianmoooore]

You will get a barely noticeable improvement in performance and fuel consumption by removing the cat., which you can legally do, if either the engine was manufactured before August 1992, or the car was first used before August 1992.

[mirage]

thanks for the advice mate....ill stick with it then...