There are several regular maintenance things you can do , to miminize this.
Use Chevron Techtron cleaner in your gas.
Change oil and filter and use quality oil such as Penzoil Platinum Syn 5-30 or 0-20 and toyota brand filter.
Clean your throttle body with Throttle body cleaner and clean MAP sensor with MAP cleaner (instructions are on this forum).
Make sure you have a Clean quality air filter.
Clean or replace PCV valve. Only replace with Toyota orginial.
Make sure you dont have any loose vacuum hoses.
Replace sparkplugs, if over 100k miles. Only use denso or toyota.
Use good name brand gas.
Thank you. I will definitely use OEM Toyota oil filter. and I can use Chevron cleaner without having to wait for oil testing analysis, as I think it will not interfere with the results. I actually just fixed one of the broken vacuum hose connection to air box and changed the filter while at it. PCV valve & spark plug recommendation for the sound or avoiding sludge?