OBD2 code P0303...Misfire on cyl 3

[zx150]

I've got an '04 Astro AWD and just took it in a 2500 mile road trip. Towards the end of the trip the check engine light starts flashing and the code is a P0303 misfire on cyl 3. Took a look under the hood and the spark plugs are extremely hard to get to. Took it to my mechanic and they wanted $1200 to repair it.

I'd like to tackle this myself; do all 6 plugs, wires cap and rotor.

Any tricks for doing this? What's gotta be removed to access everything? What kind of time frame does it take to change it all out?

These are all the codes it throws:
PO200
PO303
PO442

Thanks for the help!

[2002Safari]

Take a look through these articles:
http://troubleshootmyvehicle.com/gm/4.3 ... articles-1

It's a job changing plugs and wires. With the codes you posted you may have more problems than just plugs, wires, cap and rotor. Do a bunch of research before taking off on the project. I just finished replacing intake manifold gasket on 2002 Safari. It takes a while to accomplish. I did lots of cleanup because of grease and grime that had built up over the 10 year 156k mile span.

[LiftedAWDAstro]

If a tune-up hasn't been done I would start there. You are looking at 4-6 hours for your first time. They are a bugger to get to. Look in the General Procedures section for a how-to on doing them. Only use AC Delco parts or you'll have to do it again soon! I order parts from RockAuto.com. Not cheap but worth the money.