ygha

Currently, I have stock reso with just 3" straight pipes and dual tips. (no reso-back mufflers ... )

And I'm thinking of removing 2nd cats ...
The qustion is ...

- Will I lose low-end torque?
- Will the sound and cabin drone be too loud?

shardul

iTrader: (1)

you may not loose any low end torque since you still have the stock resonator in place.

cal1

I removed the 2nd cats on my SL55. I did not notice any loss of low end torque and thought there may have been a slight improvement at mid and top end. It could just be the additional growl that made me think so. There is some increase in cabin noise, but not too noticeable until I get on the throttle. I'm running shorty headers with stock AMG exhaust except for the 2nd cat delete.

Timeless

I was always under the impression you lost low end torque doing this.

Is it only if you do both res and secondary cats at the same time? Basically leaving either the res or secondary cats in place will leave the low end torque in place?