Does neone have this on their car?? do u get a check engine light, and can u feel a difference wiht it on with ur 3" downpipe if you have one?

 

You shouldn't be getting a CEL with the Helix HFC. However, you can run a mechanical cel fix just to be safe. Helix cat is metal-substrate which will outflow and outlast a traditional ceramic cat. The thermal barrier heat-shield assists in rapid warm-up of the cat for maximum efficiency and helps to keep exhaust gas velocities high.

Thanks,
Tom