Oxygen Sensor Location

DAVEGOYA

MEMBER
2001 ACURA MDX
6 CYL
4WD
AUTOMATIC
70,000 MILES

My car get scanned and they found a code PO135 and tell me to replace the oxygen sensor1 in bank 1. I bought the sensor and I want to do it my self. But I don't where is this sensor. I saw a few of this sensor in the motor. And I don't wich one I'm going to replace. If you can help me with a diagram. I can appreciate that. Thank you

5 Replies

RASMATAZ

MECHANIC
75,992 POSTS

B1S1 is on the exhaust pipe upstream from the catalytic converter. The other is on the C/Converter. Here is a guide t help walk you through the repair and the location of the oxygens sensors in the diagrams below.

https://www.2carpros.com/articles/how-to-replace-an-oxygen-sensor

Check out the diagrams (Below). Please let us know if you need anything else to get the problem fixed.

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Monday, September 1st, 2008 AT 5:09 PM

KHLOW2008

MECHANIC
41,814 POSTS

Hi davegoya,

It is the primary sensor.

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Tuesday, September 2nd, 2008 AT 8:58 AM

HUNDRIVER

MEMBER
3 POSTS
2001 ACURA MDX
6 CYL
4WD
AUTOMATIC
115,000 MILES

I have replaced the original oxygen sensors, Denso, with non-OE sensors, Bosch. I cannot clear the CE nor the VTM-4 lights. I also cannot engage the VTM-4 system. On computer analysis, the DTC still indicate the O2 sensors. As an electrical engineer, I am somewhat confident I installed them correctly. The MDX runs fine with no apparent problems. I am confused. Please help.

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Monday, April 13th, 2020 AT 6:18 PM (Merged)

JEREMIAH

MECHANIC
217 POSTS

Check to make sure that the correct sensors were installed in the right order. The primary is an air/fuel sensor and the secondary is the heated oxygen sensor. Two different sensors that are not interchangeable.

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Monday, April 13th, 2020 AT 6:18 PM (Merged)

HUNDRIVER

MEMBER
3 POSTS

They both are 4-wire sensors. Two wires in each are listed as a heater circuit. I have rechecked the color codes and signal wires between the OEM and bosch wire color coding. I have cleared the VTM light but not the CEL. I'm now getting P0135, P0141 and P0133, indicating oxygen sensor heater circuit. The MDX still runs fine. I am perplexed.