need help .... backfiring
 

My 2002 has started to back fire.
I know she is in need of a tune up, but not sure what is going on.

Any help would be great.

any cel??? give it a good tune up and see what happens... backfires are fuel getting into the cat and igniting which can kill the cat

Ok.

My bf tried to help me with the tune up, but the plugs are in really tight.

ya there hard to get to youd prob have a better chance because of the smaller arms. i had to have my little sister get a couple of plugs out of my car because my arms were too big. also try going in from the bottom some say its easier like that

do you have a check engine light???

Yes. But it due to the o2 sensors.

I can have it read again.

the o2s measure the exhaust pre cat and post cat if there not in the proper range of each other the computer compensates for it causing the cel id bet the tune up will fix the problem (and replace the o2s there probably fouled)

Ok. I will try that and see what happens.

Moving this to the 4th gen LS section....

Ok. I talked to a good mechanic friend of mine. He is gonna do the tune up, change o2 sensors, clean my engine bay really good, and weld my sub frame connectors. For $100.

So in about a week she will be going in for some work. And i feel bad.... i love my car, i try to do what i can for it with what i have. But i have kinda neglected the car recently.

Backfire is not caused by a need for a tune up, nor would bad O2s. If that was true, most cars on the road today would be backfireing. You have unburnt fuel yes, most likely caused by bad gas, or running anything other than 93 octave, or the computer is not functioning properly. In order for the plugs to cause backfiring, they would have to have literally nothing left of the electrode, which at that point, the car wouldn't even run. Since you and your boyfriend seem to have limited skills, I would take it to someone who specializes on these engines. If you told your mechanic what the car is doing, and he says he'll do the tune up and O2s, then either he knows that won't cure your problem and would be doing it just to get your business or he isn't very knowledgeable. Take it to someone who knows these engines well.