How difficult is it to change the spark plugs in the trailblazer? Can you do it by yourself? I have a misfire in cylinder 3. Any suggestions? Thanks!

 

It is the 4.2 Vortex motor, 2002

 

use only Iridium plugs in these engines there was a guy earlier was changing plugs every month he was using cheap Autolite FORD plugs .....Iridium plugs are guaranteed to last over 100,000 miles

 

remove the top cover under it you will see the coils with an electrical plug and 1 bolt remove the bolt carefully lift off the coil the spark plug is directly
underneath you need the plug socket with the rubber inside to hold the plug to take it out do this 6 times replace the plugs with Iridium plugs then replace the coils and the top cover and any small hoses you removed