easy question for yall mechanics

[kunder3006]

I have a 2002 GMC Z71 4.8 liter, check engine light came on, used a code reader and the code read ....number 2 cylinder misfire my question is which one of the eight is number two, gonna start easy, plug,new wire, then work up from there, coil pack...what from there do yall think....all help is welcome...
Thanks Kenneth

[Johnny Dangerr]

The one opposite #1

Wheeee

[clintb]

Get a chiltons to check order, Yes, change the plug

[wellsm11]

#2 is the front plug on the pass side of the engine compartment

[h2447intx]

really easy to test , start car truck what ever ,, pull plug wire one at a time the one that makes NO diff in idle when pulled is the one that is bad

[h2447intx]

should be first cylinder on the left of motor when you pop the hood


got this pic of the net !

pull # 2 and see if there is a diff in idle

Firing Order 1-8-7-2-6-5-4-3

you can double check but i think this is the firing order

[on-a-mission]

http://www.fixya.com/cars/t3576083-firing_order_diagram_2002_tahoe

Not a Z71 but should be the same

[kunder3006]

thanks all

[safetyman]

you should never pull a plug wire with the motor running........not good on the coil.......

your plugs may need changing but dont old school try to diagnose your late model vehicle.......the plugs in your truck should be Platium tipped and are good for 100,000 miles......if you change them ...be sure to put the right plug with the right gap back in

sometimes misfires happen for a number of reasons......doesnt mean that the plug needs to be changed.......the code it shown you is considered a soft code and will go away if the problem stops

Like clint said get a chiltons....or better yet if you have the coins get a true shop manual from Helms http://www.helminc.com/helm/homepage...1.5l7l0&oq=+he

good luck

[Goldeneagle]

Check for a worn plug boot on the wire. Had one doing the same thing and it was firing out the side of the boot. Rubber was weather cracked.