Finally got my ultimate racing catted down pipes installed in the x5m. I also opted to go for the catted o2 bungs / extenders to further reduce any type of CEL.
i know its a diff engine but on my e92 m3 i went w/ just o2 extenders and the CEL goes off but comes back on every few thousand miles and goes back off on its own.
the pipes were installed @ Car Authority carauthority.net in Fredericksburg VA as they provide pick up/drop off or tow service if requested.
Total install time was 9 hours . ( other shops quoted as high as 11 hours).
Install cost was around 800 bucks including pickup/drop off.
Now for the performance
Cold start is a bit louder and normal idle is a few db's higher. Driving in D , the power band was much smoother with just a slight increase in cabin noise. In S And M mode with Power going through 2nd and 3rd i immediately felt the power surge/increase and a slight difference in exhaust back fire / burble.
After i drive it a few more and compare to my buddies stock x5m i'll get my tune
videos of the exhaust sound coming up.
All in all pretty good for under 2400