Code P0143 bank 1 sensor 3

AARONCH88

MEMBER
1997 ISUZU RODEO
3.2L
V6
4WD
MANUAL
187,300 MILES

Had check engine light coming on for code p0143 oxygen sensor low voltage. I cannot really get any information on where it is on the car and the auto part stores do not really know either. Going to try and replace myself. Anybody ever have this code problem or sensor problem?

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2 Replies

PATENTED_REPAIR_PRO

MECHANIC
1,853 POSTS

On underneath vehicle, forward of TWC converter.

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Wednesday, December 27th, 2017 AT 6:24 AM

PATENTED_REPAIR_PRO

MECHANIC
1,853 POSTS

Bank 1 is the same bank where number one cylinder is. Here are some troubleshooting steps:

Diagnostic Aids

Check for sensor pigtail contacting exhaust system. Ensure PCM grounds are okay. Check fuel pressure. Perform INJECTOR BALANCE TEST. See FUEL SYSTEM in appropriate SYSTEM/COMPONENT TESTS article. Check vacuum hoses for leaks at intake, throttle body, PCV and EGR systems. Inspect exhaust system for leaks. MAF sensor can go lean, disconnect MAF and recheck.
1. Perform On-Board Diagnostic (OBD) System Check. See BASIC TESTING article. Go to next step.
2. Start engine and allow it to reach normal operating temperature. Ensure no related DTCs are present. Observe HO2S No. 3, bank 1 parameter on scan tool. If display is not as specified, go to next step. If display remains less than 22 mV, go to step 4).
3. Turn ignition on. Review and record FAILURE RECORDS data on scan tool. Operate vehicle within FAILURE RECORDS conditions. If DTC P0143 is set, go to next step. If DTC P0143 is not set, check for an intermittent problem, see DIAGNOSTIC AIDS .
4. Turn ignition off. Disconnect PCM harness connectors. Using an ohmmeter, check HO2S No. 3, bank 1 high and low signal circuits for a short to ground or HO2S heater ground circuit. Repair as necessary. Retest system. If wires are okay, go to next step.
5. Disconnect HO2S No. 3, bank 1 harness connector. Check HO2S No. 3, bank 1 high and low signal circuits for a short together. Repair as necessary. Retest system. If wires are okay, go to next step.
6. Reconnect PCM harness connectors, leaving HO2S No. 3 disconnected. Turn ignition on. Using scan tool, observe HO2S No. 3, bank 1 parameter. If display is 425-475 mV, replace HO2S No. 3. If display is not as specified, replace PCM. Retest system.