I changed the manifold for the Librands version last April, leaving the rest of the exhaust as standard. It has made a huge difference to the car, much more responsive, will actually do 30 mph in 4th and the fuel consumption has improved to an average 37 miles to the gallon. Yes you get a different engine note which I like and some pops on over run when changing down.
So far I have not gone for any ECU upgrade
2018 Plus4 so the GDI engine
Tim
