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JBA Header Install Instructions

  • Go to Lowes or Autozone and purchase every version of 12mm wrench that you can find. It’s always best to have it on hand, and whatever you don’t use you can always return.
  • Remove the catback and tailpipe. Unplug all 4 o2 sensors. Disconnect the front of the driveshaft from the front diff (if 4×4) and swing it out of the way, you can keep the rear of the driveshaft connected. Remove the mid pipes (you’ll need a 14mm socket, a few extensions, and a ton of torque (I use a pneumatic impact) Toyota torqued these on super tight for some reason.
  • Remove the heat shields from the stock manifolds, remove the stock manifolds. At this point you should be about an hour into your install including jacking up the truck.
  • Slip the driver side Long Tube header in place. Thread on the second from the front lower nut onto its stud first. If you don’t thread this nut on first, you will have to remove whatever nuts you do install to put this nut on it’s stud.
  • Thread the rest of the nuts onto their studs. Tighten all finger tight at first, then working your way from middle to outside hand tighten all 8 nuts. At first tighten each nut 1/4 turn, then half turn, Then tight, then tighter, and finally as tight as you can with the box end of the 12mm wrench that you’re using.
  • Try to slip the passenger side header into place, note where the air injection flange contacts the cab. Take passenger side header back out of truck, use a 6lb persuader to massage the cab of truck until header slips into place.
  • You can thread all 8 nuts into place on passenger side header in any order, but make sure to use tightening sequences described for driver side header.
  • Apply a very thin layer of Copper RTV (from AutoZone) on all of the flange mating surfaces. Loosely bolt up mid pipes/V band clamps, Also loosely bolt up catback. The only reason you’re bolting up catback right now is to generally point the mid pipes in the right direction.
  • Slowly start to tighten the v band clamps. Twist and wobble the mid pipes as you tighten V band clamps. Pay attention to where the rear of the mid pipes is falling, you need to make sure that the rear flange is generally lining up with the front flanges of the catback. Don’t overtighten the v band clamps or you will strip the threads and the clamps will need to be replaced. Tighten just enough to keep the mid pipe from wobbling/twisting.
  • Before tightening up the catback to mid pipes flanges, install the tailpipes. Finger tighten their bolts. Adjust and level the tailpipes from side to side. If necessary, now is the time to slightly twist the catback to get the tailpipes to be level with one another. When tailpipes are to your satisfaction tighten all bolts, I usually torque to spec using a pneumatic impact.
  • Apply anti-seize onto all 02 sensors. Install front position 02 sensors into primary tube bung. Use supplied plugs to plug header collector bungs. If you’re installing an AFR gauge the collector bung is the best place for it’s 02 sensor. Install rear 02 sensors, you may need to switch rear 02 sensors from side to side depending on which options you chose for the mid pipes, call for details 760-877-4234.
  • Confirm all bolts are tight, re-install front of front driveshaft onto front diff, use red loc tite on the bolts.
  • Start truck, confirm there are no exhaust leaks by holding your hands near all connections and feeling for air leaking out. Test drive listening for leaks, if you hear any put your hands near where they may be and feel for air leaking past the connection.
  • Our valvetrain is very noisy. Thin pipe long tube headers exaggerate the sound from the valvetrain and can sound similar to an exhaust leak. Always confirm suspicion of an exhaust leak by putting your hands near the suspected leak and feeling for air leaking past the connection.
  • Confirm that 49HP and 89TQ was gained to the rear wheels by completely disabling traction control and mashing the throttle to the floor. You will notice that there is no issue burning the tires thru first and second gear 😉