Hi Guys, Just had a custom downpipe on my car removing the cat. everything is ok except when i had a little run down the motorway when i reached around 100 mph the car stuttered i tried it again and it kept doing it. is this because the ecu isnt used to the emissions going through it? not sure feels like an over boost or summit? plus a im a not going to get through an mot i wanted to try and locate a spare cat, in the unlikey case of not bein able to get it through a mot. would ne one have one for sale?? Thanks alot for readin. Jinx Birmingham