Review on Flowmaster 2000125 Catalytic Converter Univ 200 Series: High-Flow Metal H.F. 2.50 by Marc Salem

I really like these Flowmaster High Flow cats, they have significantly increased gas mileage but I have two downsides. First, it keeps reporting my passenger side O2 sensor as bad but not the driver side. Second, my engine's temperature rose almost to the point of overheating. I cut them off after only 150 miles and weld them back to my standard crampons.