Toyota Prius Spark Plug Installation

These installation instructions are good for Prius Hybrid years 2004, 2005, 2006, 2007 and 2008.

You will need:

– 12mm and 10mm sockets
– 5/8ths deep socket
– Ratchet
– Tool to remove plugs
– Spark plugs to install (gapped to .040″)
– ~20 minutes

First, remove the two 12mm bolts on the sides of the relay housing (marked in yellow) and it pulls back out of the way.

Next, remove the four 10mm bolts holding the individual coil packs in place (marked in green). Believe it or not, that’s all the bolts you have to remove to do this install.

The coil packs pull straight up and the plugs are right down each hole, very easy to get to. You don’t need a torque wrench for the install but if you do have one you’ll apply 20 Ft-Lbs. If a torque wrench is unavailable you can thread the plugs by hand until they seat with the engine and then turn them another 1/4 turn.

When you’ve installed the 4 plugs you follow the same procedure in reverse to put the car back together.