Mechanics

NEED TO KNOW WHERE 02 CENSOR IS.

2001 Mitsubishi Eclipse

Engine Performance problem
2001 Mitsubishi Eclipse 6 cyl Front Wheel Drive Automatic 91247 miles

I have error code PO141 - " 02 censor heater circuit malfunction Bank 1 Sensor 2". I need to know which 02 censor this is in relation to the car. Do you have a diagram or very good directions on exactly where this 02 censor is so I can change it out? Please advise. Thank you!
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Kerney_Inc
September 21, 2008.




DTC P0141: REAR HEATED OXYGEN SENSOR (HO2S) HEATER CIRCUIT MALFUNCTION (BANK 1 SENSOR 2)

On 3.0L vehicles, this code applies to rear HO2S on right bank.(After catalytic converter )

DTC Set Criteria
Engine coolant temperature is more than 68 °F (20 °C). Battery voltage is 11-16 volts. One monitor runs each drive cycle while rear HO2S (2.4L) or right rear HO2S (3.0L), heater is on. Code will set if heater current of rear HO2S or right rear HO2S, heater is less than 0.2 amp or more than 3.5 amps, for 6 seconds.
Probable Causes
-- Open or short in rear HO2S (2.4L) or right rear HO2S (3.0L), heater circuit.
¨ Open circuit in rear HO2S (2.4L) or right rear HO2S (3.0L), heater.
¨ Engine Control Module/Powertrain Control Module (ECM/PCM) failed.

Diagnostic Procedure (3.0L)

1. Turn ignition off. Disconnect right rear HO2S connector. Check right rear HO2S connector for loose, damaged or corroded terminals. If problem exists, repair connector, then go to step 12. If problem does not exist, go to next step.
2. Measure resistance between right rear HO2S connector terminals No. 1 and 3 (component side). Resistance should be 11-18 ohms at 68 °F (20 °C). If resistance is as specified, go to next step. If resistance is not as specified, replace right rear HO2S, then go to step 12.
3. Turn ignition on. Measure voltage between ground and right rear HO2S connector terminal No. 1 (Red wire). If battery voltage exists, go to step 5. If battery voltage does not exist, go to next step.
4. Turn ignition off. Remove MFI relay from engine compartment relay box. Check MFI relay connector for loose, damaged or corroded terminals. If problem exists, repair connector, then go to step 12. If problem does not exist, repair Red wire between MFI relay and rear HO2S, then go to step 12.
5. Turn ignition off. Reconnect right rear HO2S. Turn ignition on. Measure voltage between ground and ECM connector C-51 terminal No. 51 or PCM connector C-52 terminal No. 27 (Brown wire) by backprobing. If battery voltage exists, go to step 8. If battery voltage does not exist, go to next step.

6. Turn ignition off. Check ECM connector C-51 or PCM connector C-52 for loose, damaged or corroded terminals. If problem exists, repair connector, then go to step 12. If problem does not exist, go to next step.

7. Check for open or short in Brown wire between rear HO2S connector terminal No. 3 and ECM connector C-51 terminal No. 27 or PCM connector C-52 terminal No. 27. If problem exists, repair Brown wire, then go to step 12. If problem does not exist, replace ECM/PCM, then go to step 12.

8. Turn ignition off. Check ECM connector C-51 or PCM connector C-52 for loose, damaged or corroded terminals. If problem exists, repair connector, then go to step 12. If problem does not exist, go to next step.

9. Check for damage to Red wire between right rear HO2S connector terminal No. 1 and MFI relay connector terminal No. 1. If problem exists, repair Red wire, then go to step 12. If problem does not exist, go to next step.

10. Check for damage to Brown wire between right rear HO2S connector terminal No. 3 and ECM connector C-51 terminal No. 27 or PCM connector C-52 terminal No. 27. If problem exists, repair Brown wire, then go to step 12. If problem does not exist, go to next step.

11. Test drive vehicle following OBD-II drive cycle other monitor pattern. See OTHER MONITOR under OBD-II DRIVE CYCLES under VERIFYING REPAIRS. Check for DTCs. If DTC P0141 is output, replace ECM/PCM, then go to next step. If DTC P0141 is not output, problem is intermittent.

12. Test drive vehicle following OBD-II drive cycle other monitor pattern.

BMRFIXIT
Sep 21, 2008.
You have 4 of them

B1S2 is the O2S on the exhaust manifold close to the firewall follow it to the back should be right after the catalytic converter.
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Rasmataz
Sep 21, 2008.

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