Will a bad o2 always throw a code?
 

My car is running ruff , I have narrowed it down to the o2s because I just changed the opti and plugs/wires

I replaced the stock ones with bosch 02s about 20k miles ago.

Im not getting any codes consistantly, what I mean by that is ones in a while ill get the SES light to flicker then stay on but if I let the car sit the SES light wont come back on when i turn it on

Im looking for some place to scan my car but since its a 93 im kinda having trouble

No they wont always pop a code, get AC Delco next time. I have had problems bosch before.

There are many other options that would make you car run rough.

What should range should the o2's be reading if I were to get the car scanned?

yes
 

760 800 900mv yes they will throw codes after you erase them it takes a while for them to come on again.

Re: yes
 

so what does it mean when one of my 02's is stuck at 430-440. My ATap scanning shows that its not jumping around. I'm kinda a noob so pardon if I sound like a jackazz. Thanks.

The O2 sensors could be gone and the car would not run rough. It would just drink gas like there's no tomorrow.

sounds like ignition to me.......sure everything is good. You can crack plugs when putting them in.

Like stated above 02's will just drink gas, like 10mpg. But one time i took it into the GM dealorship when it was running rough and they said it was the EGR system....i was like ummmmm no it's ignition. So they garentee its the EGR next day i'm back getting free plugs and wires put in:D But then again maybe the EGR could cause it......They felt dumb.......expecially after i told them what it was.;)

O yea the SES light would come on sometimes i believe too. Best way is to scan it:bow:

The reason I changed the o2's is because one was ruff , it was tripped the SES light and made the car run rough, I knew a guy at a chevy dealer and he scaned it for and sure enough , one of the o2's werent dancing . I changed them both and problem fixxed.


I just swapped the opti because my car was running like this and I thought the opti was my problem, I hope i didnt get bad opti

I think i found a guy to scan it