From personal experience avoid CATS DIRECT like the plague.
The CAT they supplied me lasted for 14 months (i.e. got me through one MOT, but not the next one) and they were absolute pigs when it came to refunding under guarantee, citing all manner of BS.
I eventually got my money back and replaced with a known good (2nd hand CAT) from Autolusso.
My advice is to purchase a known good (i.e. expensive) sports CAT from the likes of Alfaholics, or an OE 2nd hand CAT from a reliable source, such as AL.
The cheapy (<£200) aftermarket CATS all have significantly less precious metals within than an OE unit, hence the limited shelf life.
From memory I paid about £70 for the OE unit from AL - although this was 5yrs ago now!
p.s. no CAT at all will fail the MOT spectacularly. Some clean burning (older) engines will go through an MOT without one, but a TS is not one of them!
-1998 916 Spider 2.0TS Lusso-
H&S Corse stage 1.
CATCAMs stage 1 cams with Savali custom ECU remap.
305mm discs with 166 4-pot callipers.
Ragazzon exhaust mid section.
Biscione Racing 2x70mm rear section.
17" Zender Siena wheels with 3mm rear spacers.
etc etc etc!