What is the best cat to remove for more power? i would like to keep one on for mot time. I thought the downpipe one would be best removed but not sure. Help!

 

i wanted to ask this question today!
looks like johnny got there first.............but from wat i have heard the most gains seem to b, like johnny said, from the downpipe- any1 out there confirm this?

cheers

Mo

 

Anyone? where's greasemonkey when you need him? lol.

 

done the down pipe on mine a couple of weeks ago by far the best power gain than any other mod for that price

 

more power gains removing the downpipe one. but its debatable whether you'll pass an mot with only a centre cat...

 

Lol! Was out having a life Johnny!

Which cat you'd want remove first depends largely on what age of car you have, how much of a consideration warranty preservation is, and whether you want your car to have a chance of passing an MOT emissions test without swapping exhaust parts.

Most turbocharged Imprezas have two catalysts, one in the downpipe, and one in the mid section of the exhaust system. Fitting a well designed cat-free downpipe will make by far the most noticeable difference.

If you have an MY01-02 WRX with an up-pipe cat, removing this is probably best done after the downpipe one.

 

cheers greasemonkey, i have my95 sti2 with no warranty so the downpipe one is going. shouldn't be a prob with my local mot station (although he tried to fail me on headlight beam projecting the wrong way and blinding other drivers until i explained japs drive on the left) lol.

 

As mentioned the downpipe will produce more gains and come MOT time make sure the car has gone for a good blast to make sure everything is nice and hot, you should pass with the centre cat warmed up nicely.
Daz.