The install on my Sequoia V8 went really smooth, took me about 2 hours but I did it slow and cleaned my MAF before firing it up. Just sounds like a lot of air at idle and lower RPM range but really growls above the 2,800 mark and roars above the 3,600 mark. I did notice a 1-2 mpg improvement at highway speeds, but that could just have been from cleaning the MAF sensor, not a whole lot in the lower cruising rpm range but the acceleration is noticeably better especially above the 3,000 mark
This unit was very easy to install. K&N included everything that was necessary. I like the fact I did not have to make any modifications that I can not change back to factory if I want to. The Sequoia definitely breathes better now. You can here the difference when accelerating, there is a definitely throaty sound. Very similar to the sound a four-barrel carb made on a pre-emissions era V8. I have not had a chance to check the mileage yet, but it seems to be making a difference.
K & N 77 Series in 2008 Sequoia - Mixed Review
I recently bought, installed, spend two weeks with, then removed the K & N 77 Series cold air induction. There are hight points, but for me, it was ultimately far too loud to live with. Quality of matierals appears to be good. The heat sheild is basis, but it went together fine. The polished air tube looks nice. All bolts, nuts, etc were included. Installation took about 2 hours and I'm no gearhead. All went well with one exception: The intake tube just doesn't fit quite perfectly. It fits - just not like a glove. It is supported at the heat sheild by one bolt. It seemed like the mounting point on the tube should've been rotated radially around the tube about 15 degrees or so. As such, the angle the tube hits the throttle body is not quite straight, which is allowed for in the rubber coupling, but it could've been better. As a result, the tube is rotated slightly rearward and contacts the plastic engine cover. This requires that you trim the cover a little bit. Easy, but could've been avoided. Performance: If you want loud, you'll love it. I was seeking a little more sound, but expected nothing like this. It's pretty loud. Sounds good under full throttle. At moderate throttle it can drone a bit. Claims of improved power and throttle response might be true. All in all, if you want to really hear the engine, all the time, you will be satisfied. If you're like me, and you just wanted it to be a little more throaty, it might be more than you are asking for.