In this video we install Doug Thorley 421 headers on our 2004 V8 4th gen 4runner. Towards the end of the movie, we do a sound comparison and dyno it. We make at least 37.4 ftlbs more torque!!! We plan to tow our track miata with this 4runner so every bit more torque helps. This vehicle has been completely transformed!

We did all of the common boltons at the same time:
Doug Thorley headers installation
YPipe Installation
O2 simulator installation
Gibson catback exhaust installation
Volant air intake

Parts:

Doug Thorley Headers (off road use only): https://www.urdusa.com/thy564ylsc...

YPipe: https://www.urdusa.com/89253dougtho...

O2 simulator (off road use only): https://www.urdusa.com/urdrearsenso...

Gibson catback exhaust:
https://www.summitracing.com/parts/GI...

New Fastenal engine mount hardware (class 10.9):
https://www.fastenal.com/products/det...
https://www.fastenal.com/products/det...

NGK spark plugs:
https://amzn.to/2Sq4zFr

Rubber splash guards/rain guards:
https://amzn.to/2SmVgWQ

Milwaukee Cordless Ratchet:
https://amzn.to/2HSHh9a

Milwaukee 1/2" Impact:
https://amzn.to/3lgzIYu

BudBuilt Skid Plate (AL, bare metal):
https://budbuilt.com/FrontSkidPlate...

Headlights (custom FXR Bixenon projector retrofit on OEM Toyota headlights):
https://lightwerkz.net/

Music by Kurtis Tyler (check out his Spotify!): https://open.spotify.com/artist/5nVCW...