There are no resonators in the OEM or TRD system. I'm well versed in auto mechanics (30 years working on cars) and do much of my own work on my vehicles. There is no room for a resonator of any meaningful size (i.e., 12"+), unfortunately. The muffler on either system is too long and there is no room before the exhaust pipe goes over the axle and there's little room forward of the muffler and aft of the catalytic converters. Also, resonators won't do much for volume, they just smooth out the sound. We really need a second small muffler which defeats the purpose of a high-flow system.
LOL.
I yanked the TRD exhaust and put the OEM exhaust back on my wife's 2020 4runner a couple weeks back. The truck is SO MUCH BETTER. It's quiet, smooth, and oddly, I swear it feels more responsive. Even the 4-5 downshifting which is common on the highway is no big deal now because you hardly hear it. I love driving it now. Of course, my wife misses the sound and hates that her 4runner sounds like all the others. I think she's off her freaking rocker in thinking that the moaning/droning TRD exhaust sounds good.
If I have to put that POS system back on, I'm wrapping the muffler in exhaust insulation and the exhaust pipe in heat wrap. I don't give a flying fart if I rot that system by doing that. I'll also cut the TRD tip off and add a resonated one and install one or two exhaust inserts:
2.5" Exhaust Cone Insert Sound Reducer | ZZPerformance. We're talking $300 in mods to the exhaust system and sound insulation and I still doubt it will do much.
I can't stress enough how much the TRD exhaust degrades this truck. I'm all for good sounding exhausts (my BMW M235 has a high flow downpipe and catback), but you can't make an naturally aspirated V6 sound good. Impossible. Period.