Downpipes make the driver feel good unless a corresponding tune is installed. Same with $$ for exhaust and for intake filters and airboxes. IE you have to void your warranty to take advantage of these mods. The only way to get warrantied power is to always travel downhill.
Definitely agree not normal but does not sound engine to me. Deceleration could be engine moving to driver side (normal) and exhaust or cover rattling or something like that. But hard to tell with that sound recording
I would keep the same grade but switch to a high quality oil like Amsoil. If you had engine problems and the dealer found out the change then it would be a world of hurt for your wallet.
If you put a mike under every modern car hood you would get same or similar sounds. Easiest fix is Dynamat under the hood and it can be applied everywhere so better than those sound mats from the factory. USA has to get used to 4cyl sounds. Unlikely this kiwi would complain as I grew up with 4...
If you want a black emblem take it off, rough it up with sand paper, spray adhesion promoter on and paint with matt or shiny black. Don't need to waste a pile of money on a badge - save it for lockers, suspension or shocks etc.
With front lock on IFS systems one has to be real careful when to lock and unlock due to CV joint/axle failure. Friend has a previous gen (2020??) 4 Runner with factory rear and added front lock and makes a huge difference. Eaton should be ok for front and rear if Toyo are not available...
Go under the seat and find the sensor and depending on the logic you either have to short it across the terminals or leave it open circuited. Try that and just reconnect when you go to sell. Could be needing a resistance though so run an ohmeter across the sensor terminals with someone sitting...
Last time something like this happened to me was a splined shaft on a Jeep. Turned out to be dry and had worn the splines so it vibrated. For some reason manufacturers don't want us peons to grease joints, suspension and driveshafts etc. The fix is probably disassemble, add a grease nipple...
Ditch lights?? You planning on diversions into ditches soon? Sorry night time is for beer drinking, camp fires and music not wheeling. Especially where we go in the Rockies. Too much potential damage at night. Pretty good mod list though
Almost drives one to simply buy a TRD OR to not get all that fancy crap. I actually don't need Adaptive Cruise because I am old fashioned and keep my eyes on the road. Don't need ABS brakes either or lane departure or blind spot monitoring etc. Heard the TH is a bear with all the sensor...