Originally Posted by 156_TSpark_Boy
So whats the set up with the 156? is it the same as the 147 - Pre cat - cat - centre box - back box.
I've never understood the pre-cat, is it in the manifold or just after it?
Depends if it's the CF2 or CF3 engines.. what year is your car? The CF3 was after 2000 IIRC.
This engine has precats and takes 4BHP off your output, giving you 140BHP instead of the earlier 144BHP.