location and number of O2 sensors on a '96 LT1

[96 BAM]

Can someone please let me know how many O2 sensors there are on a '96 and their locations. I am experiencing a rough idle and considering replacing all of the O2 sensors.

[LT4man]

Four (4) oxygen sensors.

One in front of each catalytic converter.

One behind each catalytic converter.

The sensors compare the the oxygen content in the exhaust as it exits the exhaust manifolds to the content as it leaves the converter.

SAVE the WAVE!

[LT4man]

The oxygen sensors last a very long time. I have over 125,000 miles on my original ones.

There are quite a few things which will cause an LT1/LT4 to idle poorly.

The oxygen sensors will illuminate the CEL and store a trouble code if they are malfunctioning.

No codes set?

Then I would start by searching for vacuum leaks or ignition faults.

SAVE the WAVE!

[96 BAM]

Thanks for the info. I cannot locate any vacuum leaks and have replaced several ignition/fuel system parts. Please review my previous posting for the parts that have been replaced and systems checks performed. Maybe that will help explaining the issues I am having and the reason I think new O2 sensors may be the answer. I am hoping I can get another scan later this week to see if any new codes come up.

[Hib Halverson]

Replace only the front two, if you're going to do it.

Unless you are getting "cat efficiency" codes, leave the rear two alone for now.

I'm going to guess the OP is posting more than once about this issue as, I think this is the third thread I've visited in the last few days about a 96 with rough idle.

First, ign...make sure all components are operating properly, including the distributor.

Second, vac leaks...double check.

Third, engine mechanical issues. If you have a burnt valve or a faulty camshaft lobe or lifter, the engine will idle rough.

Fourth, you can try replacing the sensors but, given a scan tester and the knowlege to interpret the data, I'd want to make sure a diagnosis was pointing towards bad sensors in-spite of no fault codes pertaining to the front sensors. If you don't have that data, replace them and see what happens.

Has the ECM memory been scanned for any history codes. if so and "H" codes were present, what codes were read?

[LLC5]

Thanks for the info. I cannot locate any vacuum leaks and have replaced several ignition/fuel system parts. Please review my previous posting for the parts that have been replaced and systems checks performed. Maybe that will help explaining the issues I am having and the reason I think new O2 sensors may be the answer. I am hoping I can get another scan later this week to see if any new codes come up.

1996 is OBD2 and would set a code if the sensors were out of spec's. I have not seen new O2 sensors fix a rough idle problem, if the sensors do indeed need to be replaced it is usually caused by another problem such as (but not limited to, although most common) fuel controls or coolant contamination. Good luck with it.