How to replace a bad O2 sensor?

[DJ Taso]

I've done some research and I think the bogging of my car is due to a bad O2 sensor and needs to be replaced or clean. Can anyone tell me where it's located and how do I go about replacing/cleaning it? Thanks in advance.

[N20LT4Bird]

If thats your car in the picture, there are 4 O2's. One shortly after each manifold on both sides and one after each CAT. If you have it scanned, you can watch and see which of them is slow or not working. Replacing them is a matter of unplugging them and wrenching them out. Then obviously wrenching them in and plugging back in. No brainer. If they are all rusty or hard to get out, you may have to get an O2 sensor socket and heat em up with a torch.

[N20LT4Bird]

DO you have an ses light on? What makes you think O2's are bad? There are many other possibilities for a bog.

[DJ Taso]

Yes. My SES light does come on. The bogging occurs at its strongest on a cold start. I give it gas and I don't go anywhere its ridiculous, honda civics pass me up After it warms up the bogging is still there but not as bad. Also, when I start my car it takes a few tries and when it does start it makes a noise like I have a cam or something (which I dont) for the first few seconds then it idles out and its all quiet. People said it's my O2 sensors, they've never been replaced. And yes, that's the car in my picture. '94 T/A

[BAS]

umm, can't be your o2's

Your O2's are used on a cold start.

Since your car is a 94, you only have 2 O2's,
not 4.

Originally posted by DJ Taso
Yes. My SES light does come on. The bogging occurs at its strongest on a cold start. I give it gas and I don't go anywhere its ridiculous, honda civics pass me up After it warms up the bogging is still there but not as bad. Also, when I start my car it takes a few tries and when it does start it makes a noise like I have a cam or something (which I dont) for the first few seconds then it idles out and its all quiet. People said it's my O2 sensors, they've never been replaced. And yes, that's the car in my picture. '94 T/A

[Jeff_in_Atl]

Ummm... Did you mean NOT used? I'm pretty sure when it is cold, it is in open loop which means the O2s are not being used for fuel correction.

I don't think it would be the O2s. You need to have it scanned and find out what the code is. I wouldn't waste your money on O2s hoping it will fix it.

[Injuneer]

If the SES light comes on, why guess about what is wrong? Simply get it scanned. Sounds to me like you may have a fuel problem... weak fuel pump, faulty check valve in the pump, or faulty fuel pressure regulator, etc.

If my car was slower than a Honda Civic, I'd spend a few $$$ and get it scanned (if you can't find someone to loan you a scanner), rather than drive it in such bad condition, and then start spending $$$$ to replace parts you're not even sure are bad.

Think about it.

As a suggestion.... set up a "signature" with info about your car... year, trans, any significant mods.... so people can give you the correct info. Not all LT1's are the same, as you can see from the confusion on how many O2 sensors you have.

[N20LT4Bird]

Re: umm, can't be your o2's

Originally posted by BAS

Since your car is a 94, you only have 2 O2's,
not 4.

Woops, the hood through me. I thought it was at least 96. Yes, 2 O2's. The problem you describe definately doesnt sound like O2's. O2's only provide a system of checks and balances. It monitors the PCM which derives its info from the other sensors. If the other sensors are doing their job, the O2 is only making minor corrections. Even if they were bad, its not enough to make you car run like total crap. Put a scanner on it!

[Joe 1320]

Yup, I agree with da "men"..... get it scanned.

[DJ Taso]

Originally posted by Jeff 95 Z28
Ummm... Did you mean NOT used? I'm pretty sure when it is cold, it is in open loop which means the O2s are not being used for fuel correction.

I don't think it would be the O2s. You need to have it scanned and find out what the code is. I wouldn't waste your money on O2s hoping it will fix it.

MY SES light does not stay on all the time, it comes and goes. I don't know anyone who has a scanner so my best odds are going to my dealership and have them take a lookt at it but what if the SES light never goes on? The morons over at my dealership would call me and say, "Uh, there's nothing wrong with your car sir, we couldn't find anything wrong with it." It's happened to me before, they're idiots. (back when I had a faulty distributor) Yesterday, for the first time, my SES light stayed on for my entire drive home. Today, after school, my car ran fine with no bogging. Some days it's bad, other days its worse but today I got lucky. Rarely happens.

*Also, I serviced my fuel injectors last summer along with new plugs and wires.

[FRMLAV8]

If the light was on, it should have stored the code in the ECM. They can hook up a scanner to it and read the codes.

You may also try Autozone or a similiar auto parts store, they will scan your ECM for codes for free!

[N20LT4Bird]

Dont go to the dealer...... Read the thread "kind of upset"

[AmericanZ28]

I had a similar problem!

A while back, my car too would bog without warning on cold starts. An SES scan showed that the sensor that sits under the TB was acting up(controls idle I think), so I checked it out and it all looked fine. However, I noticed that the the connector that plugs into it was really corroded. I replaced the connector with a new one ($24) and sure enough, my problem was solved. Disconect the connector and look at it, this might also be the problem.

[Jeff_in_Atl]

was it this? http://csce.uark.edu/~jgbertr/rb/iac3.jpg that was corrodid

[N20LT4Bird]

That is the idle air control motor. IAC. It is not a sensor. it is a step motor that works kind of like a regulated vacuum leak. It is contolled by the PCM. This is how the PCM controls how much air is coming into the engine at idle. The farther out the pintle moves, the less air moves through the passage. The closer in it retracts, the more air.