1999 Chevrolet Tahoe

Computer problem
1999 Chevy Tahoe V8 Four Wheel Drive Automatic 105500 miles

My check engine light came on and I had auto zone check it. Code came back as the Oxygen Sensor so I replaced it. I figured my check engine light would go off but it didn't. Do I have to reset the computer with one of those code readers to get it to go off? The guy at the counter talked me into some of the anit seize which is supposed to keep the sensor from welding itself to the threaded exhaust pipe. If some of that got on the sensor would it affect it? Any help would be greatly recieved and appreciated.

March 3, 2009.


What was the exact code they pulled? There are 3 - 4 O2 sensors on your vehicle you may not have change the correct one.

Here how the O2 sensor Banks work.

Bank 1 is on the Passenger Side.

Bank 1 Sensor 1 is in the exhaust manifold.

Bank 1 Sensor 2 would be the next one back or in front of the cat.

If single exhaust sensor 2 could be called the Upstream sensor, and Sensor 3 would be after or behind the cat and could be called the Down Stream

Bank 2 is the Drivers Side.

Bank 2 Sensor 1 would be in the exhaust manifold.

If single exhaust the above paragraph with the upstream and downstream sensor goes.

If Dual Exhaust then.

Bank 2 Sensor 2 would be in front of the cat.


Mar 3, 2009.
Thanks for the reply. It was showing bank one at Auto Zone with thier code reader. According to all the research I have found it only has 2 O2 sensors on it. One in the front of Cat converter about a foot below the manifold or Upstream and 1 behind it downstream. I talked to my mechanic buddy and he said the computer would have to be cleared. I will try that tomorrow when I take that wrench back to auto zone. But like I say according to them (auto zone) and my searching it only has 2. Maybe I am missing somthing. I am by no means Mr. Goodwrench. I'm more like a Lug Nut.

Thanks again.

Mar 3, 2009.