spark plug for my 2004 chevrolet trailblazer ls 2 wd?

[Jimmy]

i got 2004 chevrolet trailblazer LS v6.yesterday my cylinder #4 is misfiring so i bought one spark plug for it.my question is..is it better to just put new spark plug in all of them or it doesn't matter?
it working fine now when i put #4 spark plug
i only changed the #4 spark plug .so is it better if i changed them all spark plug

[frost1085]

if u are going to replace 1 u might as well chang all of them, that way is anything else comes up u will no its no the spark plugs. and also u might need to replace the sparkplug wire. u can just replace one especially if u are tight on money. so check the wire to because that could b the cause as well. u can look up a spark plug diagram online and check the plug to see what going on. hope this helps

[scrubbag]

You should try to figure out why your #4 was misfiring, was it a bad plug or maybe a wire? It could be firing from under the boot on the plug, causing the misfire. With all the lights off and in total darkness, if possible, open the hood and look for 'blue lights' that can be caused by leaking boots.

Ignitions have a lot of voltage now a days, and they tend to leak from many places. Inside the distributor, it can have "tracks" made by worn posts, and this dust accumulates on the inside of the cap and it can cause misfiring.

You are talking thousands of volts, so they look for an easy path to follow and will take the easiest.

That is another reason a person should not check the wires by pulling them and holding them close to the engine, the shock to the person can be deadly.

And, if your spark plug looks bad, when you pull it, then it could be that all the others are similar and probably are not to far behind the # 4 plug. So I would change them all, but first determine if you really do need to change any of them.

Look for leaks.