4.0L 2012 SR5 ?

Ive gone back to a good paper air filter.....Napa Gold. Whats up with the 2nd filter ? remove or leave in.......I would think with running a premium paper filter the 2nd filter..is just well not needed.......thoughts.....I was using a K&N but after reading about them...figured paper is better long term......took it back to where I bought it....full refund...cool

 

Since you have the 4 Litre engine, the general consistence around the forum is that removing the secondary air filter on the V-6 does not help with fuel economy or performance.
On the 2.7 Litre , 4 cylinder, the removal helps a little bit. Here is a link to the thread that will help you decide about removal of the secondary filter.
http://www.tacomaworld.com/forum/performance-tuning/2012-diy-secondary-air-filter-removal.html

Good Luck.