Cut away some piping??

Best check with the shop. If they are experienced enough they can tune according to what you want, whether better low end to better high end.
I am not sure which shop the group of Honda owners went but according to two of them their ride now better power at low end, giving quite good fc too. One Odyssey, one FD2 and one CP2.
They did different setup as all different ride and each car needed to go back for tuning a few times.....

That is because some have gone through it and with experience is still the best, rather then let the shop trial and error.
If they are good then okay, but some are plug and play shops only and will tell you it is like this one......

piping try use bigger... i used 2inch piping on my 1.5L engine...

Yours is 2.0L V6 some more. Try a bit bigger piping first.
oval midbox get a straight flow type. This type midbox there is no back pressure... it dont have spiral groove just a nice silencer hole with insulation material inside it. .. best muffler to match with NA engine is a S-Flow muffler. If you feel your current muffler is limiting you. try a s-flow muffler with twin tip outlet.

Good Read, and that reminds me that some wrap their extractor to keep them hot for faster release of the exhaust gas.....

I have a little boo boo here, i have just changed my Wira 1.5 (M) 2004 to a non branded 421 extractor with 1.7 inch piping to the end including a single bullet along the piping. The rear i just put some fake Apexi muffler (leper instead of round type exit to match my bumper).

Yesterday i drive, there was no problem with the lights on the meter gauge but today, my check engine (the one with the engine symbol with orange backlit) was on after a drive for awhile. But when i shut off the engine again for a few minutes and restarted the engine, the warning light was off.

But than it happened again when i drove around for awhile. What could be the problem?