Where is oxygen sensor bank 1 sensor 1 on Buick centruy custom 2002

Old 03-09-08, 10:29 PM
Thread Starter
Join Date: Mar 2008
Posts: 1
Received 0 Votes on 0 Posts
Where is oxygen sensor bank 1 sensor 1 on Buick centruy custom 2002

My scanner listed code P0135 O2 sensor heated malfuntion bank1 sensor 1 on my Buick Century custon 2002 v6. I am trying to locate the sensor but I could not find it. Please help.

Old 03-10-08, 04:06 PM
Join Date: Jul 2006
Location: Near Philly
Posts: 553
Received 0 Votes on 0 Posts
Quote from:http://www.aa1car.com/library/o2sensor.htm

"On most four and straight six cylinder engines, there is usually a single oxygen sensor mounted in the exhaust manifold. On V6, V8 and V10 engines, there are usually two oxygen sensors, one in each exhaust manifold. This allows the computer to monitor the air/fuel mixture from each bank of cylinders. When displayed on a scan tool, the right and left oxygen sensors are typically labeled Bank 1, Sensor 1 and Bank 2, Sensor 1.

On later model vehicles with OBD II (some 1993 and '94 models, and all 1995 and newer models), one or two additional oxygen sensors are also mounted in or behind the catalytic converter to monitor converter efficiency. These are referred to as the downstream O2 sensors, and thee will be one for each converter if the engine has dual exhausts with separate converters.

On a scan tool, the downstream sensor on a four or straight six cylinder engine with single exhaust is typically labeled Bank 1, Sensor 2. On a V6, V8 or V10 engine, the downstream O2 sensor might be labeled Bank 1 or Bank 2, Sensor 2. If a V6, V8 or V10 engine has dual exhausts with dual converters, the downstream O2 sensors would be labeled Bank 1, Sensor 2 and Bank 2, Sensor 2. Or, the downstream oxygen sensor might be labeled Bank 1 Sensor 3 if the engine has two upstream oxygen sensors in the exhaust manifold (some do to more accurately monitor emissions).

It's important to know how the O2 sensors are identified because a diagnostic trouble code that indicates a faulty O2 sensor requires that sensor to be replaced. Bank 1 is usually the front bank of cylinders on a transverse mounted V6 engine. But on a longitudinal V6, V8 or V10 it could be either the right or left bank. It may therefore be necessary to refer to the vehicle service literature to determine how the cylinder banks and oxygen sensors are labeled."
Old 03-11-08, 11:32 AM
carguyinva's Avatar
Join Date: Nov 2003
Location: Shenandoah Valley
Posts: 1,146
Received 0 Votes on 0 Posts
assuming you can identify an oxygen sensor when you see it...the real question is...does that engine use one or two upstream O2 sensors. bank one normally refers to drivers side...that being the left side of the car, stand behind the engine facing the same direction it does from rear to front (of the engine) bank one is on your left. look at the exhaust manifold on the left bank and see if you see an O2 sensor. that will be OS1 bank1. OS2 bank two would be on the opposite side in a similar position.

if it uses only 1 upstream sensor, look at the exhaust pipe after the 2 manifolds come together but before the catalytic convertor. this will also be referred to as OS1 bank 1.

disconnect the 4 wire connector to the sensor and with a voltmeter (digital, of course) check for battery voltage on one wire with the key on...you can probe all of the wires, you won't hurt anything unless you don't use a DVOM. if you have battery voltage, replace the sensor...if you don't find battery voltage, start by checking the fuses.
Old 03-11-08, 03:41 PM
Join Date: Feb 2005
Posts: 579
Received 0 Votes on 0 Posts
The O2 sensor you are looking for, is in the rear exhaust manifold just before where the exhaust bolts on. You will need to take the 2 mounts off that are on the front upper part of the engine. This will allow you to tilt the engine forward enough to get in there and replace the sensor. You can use a tie down or ratchet strap to keep the engine tilted.

Thread Tools
Search this Thread
Ask a Question
Question Title: