when do you change timing chain on 2003 Toyota 4-runner?
No. Timing belt. Not chain.
You don't as it has a chain not a belt.
In a 2005 Toyota 4 Runner : ( the 4.0 liter V6 engine has a timing CHAIN )
No . Have some mechanical assistant
In a 1994 Toyota 4 Runner the ( 2.4 liter four cylinder has a timing CHAIN ) and the ( 3.0 liter V6 has a timing BELT )
The 4.0 liter V6 engine in a 2003 Toyota 4 Runner has a timing CHAIN
The 4.0 litre V6 engine in a 2007 Toyota 4 Runner has a timing CHAIN
The 4.0 liter V6 in a 2007 Toyota 4 Runner has a timing CHAIN
The 4.0 liter V6 engine in a 2004 Toyota 4 Runner has a timing CHAIN
( NO ) The 4.0 liter V6 engine in a 2005 Toyota 4 Runner has a timing CHAIN
chain