Upstream and downstream O2 sensors??

[Bob B.]

[Keith B.]

Re: Upstream and downstream O2 sensors??

was there only a code for the O2 sensors or was there others? Did you have a scan tool that gave you live data of each sensor to see if they all where in tolerance? are the plugs clean and oil free? or burnt wires. and lastly what year are you working on?

[Joe L.]

Re: Upstream and downstream O2 sensors??

Hi all,

I know way more about old cars than I should and, accordingly, way, way less about modern cars than I should! I got a code for one O2 sensor about a heater for the O2 sensor, but I figured the best thing was to replace all four since all are about the same age.

I’m not sure what I ordered off Amazon, but what I got was four identical part number O2 sensors.

I Googled around as I did when I started and it seems that the rear pair are supposed to have heaters, meaning that the front two don’t??

If so, four of the identical part number I got must mean at least two are wrong?

When I look at C1 questions on various websites and see that it is just a bunch of people who have absolutely no hint of anything making completely wild, and totally incorrect, guesses that they think are correct, I highly suspect that what I read on the internet on something I am not familiar with is no different.

So, can anyone tell me something other than arm-waving and wild WRONG guesses?

Thanks,

Bob

Bob------


An important piece of information would be the car you are speaking of.

[Dave P.]

Re: Upstream and downstream O2 sensors??

it is just a bunch of people who have absolutely no hint of anything making completely wild, and totally incorrect, guesses that they think are correct,

Let me begin by guessing the year of the car you're asking about.

Is it a 1998? This is only a guess, but I'm a pretty good guesser. I'm guessing that I got it right.

[Joe L.]

Re: Upstream and downstream O2 sensors??

Hi all,

I know way more about old cars than I should and, accordingly, way, way less about modern cars than I should! I got a code for one O2 sensor about a heater for the O2 sensor, but I figured the best thing was to replace all four since all are about the same age.

I’m not sure what I ordered off Amazon, but what I got was four identical part number O2 sensors.

I Googled around as I did when I started and it seems that the rear pair are supposed to have heaters, meaning that the front two don’t??

If so, four of the identical part number I got must mean at least two are wrong?

When I look at C1 questions on various websites and see that it is just a bunch of people who have absolutely no hint of anything making completely wild, and totally incorrect, guesses that they think are correct, I highly suspect that what I read on the internet on something I am not familiar with is no different.

So, can anyone tell me something other than arm-waving and wild WRONG guesses?

Thanks,

Bob

Bob------


If, as Dave has guessed, the car is a 1998 Corvette, the 2 forward (pre-cat) sensors are the same and the 2 rear (popst-cat) sensors are the same.

Forward O2 sensors: originally GM #25312184 replaced by GM #19178930. The latter remains available from GM.

Rear O2 sensors: originally GM #25312202 replaced by GM #19355313. Unfortunately, the latter is now discontinued without supercession.

If you obtain aftermarket sensors, use the above GM part numbers to cross reference to the proper sensors. If aftermarket sensors do not definitively cross reference to the above part numbers, seek other aftermarket sensors that do.