symptoms of bad o2 sensor?

[98Firebird]

i think mine might be going bad... but im not sure. i noticed recently that my car was hesitating on acceleration and lacked power, so i checked the coils first, and i found that one tower on the first coil wasnt even sparking, so i replaced them all with msd coils... they helped, but theres still some hesitation and it still doesnt feel like its all there. the wires were replaced probably about 5k miles ago with taylor wires, and the plugs less than 15k miles ago. i dont know what else it could be. the car has about 75k miles on it, and im sure the o2 sensors are original. should they be replaced now? would they cause the problems im having? thanks!

[Dan Vincent]

If the 02s are original, they are surely shot at that mileage.

Get new 02s all around and you'll be set for another 60K miles or so.

[98Firebird]

well... could i just get 02 sims instead of new o2 sensors and have the problem gone? that way i wouldnt need to worry about o2s again anyway

[bradoneill]

What material spark plug you using? I had hesitation and stumbling with platinums and I switched back to stock AC delcos and it has been fine since. The guy at autozone said that some cars just only like a certain plug. I would definetly replace the O2 sensors though since the high mileage they have on them.

[98Firebird]

i have bosch platnum 4+... maybe i should switch them. but what about just taking out the o2s and putting in sims? would that fix any problems caused by the o2s?

[Nachius]

You don't want to replace the front 2 O2 sensors with sims, only the after cat O2 should be replaced with a sim.