Hi trying to decide if removing cat would be worth time and effort anyone got any information
on possible power increase + any dissadvantages
depends on the rest of the engine. on a standard car it might gain 1 or 2 bhp. On a highly tuned turbo engine though the cat would be a significant restriction.
Disadvantage is that you might have trouble at MOT time if your car is K reg or newer but it's a grey area to say the least.