My new WRX (which i absolutely love) has direct injection.
Apart from the well documented BMW and Audi (go figure
) direct injection issues with carboned up intake valves, what other cars do you have experience with that have had to have the intake valves cleaned regularly / periodically?
Most of my driving is at highway speed with the engine at 2700 RPM.
Will highway driving accelerate or alleviate this issue?
There are a few aftermarket 'fixes' available such as oil catch cans, water / meth injection, EGR delete but I don't want to interfere with my warranty to fix a problem that I may not encounter.