93 3.8L o2 sensor question

Well I have come to the conclusion that its an O2 sensor gone bad on my bird. She drives just fine and beautifuly. I changed the plugs,wires,cap, and rotor all motorcraft and pcv valve. I made a thread about it a while back with no replies. Only at a stop or sitting still idleing its a little rough. Sometimes just cruising down the road the check engine light comes on then sometimes goes off on its own.. Just wondering if this is a bad O2 sensor??? I also notice the tip of the tail pipe a little blacker then usual as well so maybe she is a tad bit rich but i dont see any black rich smoke comming out the back? Thanks in advance..
Also one more question.. Turning or going over bumps the front end squeels and makes noise bad now. Also im getting a loud clunking noise from the passenger side wheel.. Bad upper ball joint perhaps? i can say the rubber cover on it has rotted off. Thanks agian

Go to autozone and have the codes read.

guess i'll have to visit the zone.. also i hear there are 2 O2 sensors? i looked one up and it only showed 1 will that 1 fit both?

well i Havent been able to check my thread because of Katrina. I just got back online today... Anyone with any ideas of the front end squeeking?

If the boot on the ball joint is busted it could definetly be your problem. I've had to replace every ball joint on my car's front end.

thanks for replying. This forum doesnt seem to be full of action is there any other thunderbird active forum? BTW thanks for the reply! That would take care of the annoying clunking i'm getting. Should have bought the whole upper control arm assembly while I worked at O'reilly. Now time to figure out the annoying squeeling. Guess i'll try and lube the sway bar bushings and see how that turns out. Poor old car.. Now the driver window wont roll back up. Motor was just doing fine. My buddies 94 motor was fine but some sort of regulator was out in the door and replaced that and it was fine. I'll figure something out! Thanks agian!