If just done my decat manifold today and i love the noise. Its a nicer note when 2500rpm or lower and has the rasp when you floor it.
However the left hand (lower) o2 sensor doesnt sit well. Iv had to re route the o2 sensor wiring temporarily until i can get the 90 degrees sensor adaptor. Also the heat shields now don't have any fixing so cannot be re-installed therefore is causing the fan to come on as it is heating up the above coolant pipes and surrounding systems.
Power has possibly increased slightly but that could be a combo of the decat and the cobra cat back I have or placebo style feeling, almost wanting to beleive it is.
I had to get a disc cutter on one of the bolts connecting to the down pipe as it was horribly corroded and had to remove the steering UJ between the steering column and rack which was also rusted. Besides all that it was quite simply to fit. The beauty of the replacement was the incredible space you have to everything!
I got mine for £120 brand new. For such minimal money I would advise it to anyone