[SeanWRT]

I am looking to fit a catted downpipe to my m2 and stay with stock tune. At least that's what I figure works best for me.

I take it many recommend against that approach, the primary 3 reasons being:

1) DME will adjust to the freer flow so the power gain is minimized.

2) Stock tune won't take full advantage of it.

3) CEL will be thrown eventually.

On #1, I also heard that BMW turbo engine DME is load based and will not discount the power gain out of a freer flow exhaust. Not sure.

On #2, what does that mean exactly? More specific on the untaken advantages?
I am not pursuing a new high at down low or something, but instead wanting to address the significant TQ tapering down all the way to fuel cutoff, which is seen on many m2 dyno charts due to stock turbo flow limitation.
Specifically, is catted DP's PRESSURE HOLDING capability at upper range compromised with stock tune? To make no mistake, to hold the pressure, I am not asking turbo to work harder.

On #3, to be reasonable, I will accept the cat failure if it's endured heavy usage for years - stock cat can fail under excessive usage too. I'll just buy a new one.

Appreciate someone in the know shed some lights, especially on #1 and #2.