Just a quick question.

I have an Akra 4-1 pipe with a PCIII custom mapped.
If I add a TRE, do I need to re-map it?

I would, but no, you can get away with the redundant map in the digital. Anytime you mod one thing you have to change everything else to conform to that mod you made. Therefore, the reason I say I would have to map with all my mods going in.

You change mid-tune, then re-tune is watt I would do.

gumby,

Let me ask you, do you experience an abrupt off throttle response without the tre?

I had slip-ons with flies removed and the 006tre.
I put on a Leo vince full system and at the same time went with the Motty AFR.
The motty device data logs everything (almost), so didn't want to screw up the gear position with the tre (I didn't know if it would or not). So I removed the tre. The off 0% throttle response was soo bad. Sometimes in mid corner at about 6-7k rpm, I would start to crack the throttle and it wouldn't respond until what seemed like 10% with a huge kick in the butt. It was downright dangerous! I thought it was the mapping I was getting with the Motty, but I couldn't get rid of it. I put the tre back in, problem solved.

This was the first time in 8k miles I rode without the tre.

Do other people's bikes respond like this without the tre and flies removed?

I'll tell you. It runs perfectly other than the off throttle backfire (actually kind of a PUFF most of the time).
It doesn't do anything scary unless I do something stupid (which isn't out of the question).
It was custom mapped, so maybe the tuner took pains to make it right....hopefully, without the TRE.

I don't have a tre, does have flies out and slip ons, mine is smooth on and off of the throttle most of the time. the only time it isn't is in super low speed manuvering completely off the throttle then back on, like when doing a one lane u turn. I do have some decel pop though, gonna look into a custom tune to see if that will help.