Where is the ho2 sensor located? - 2000 Mitsubishi Eclipse

oxygen sensors(O2S) are located after the cat converters
heated oxygen sensors (HO2S) are located in the exhaust manifold/ exhaust pipe before the cat converters
they are different sensors performing different jobs so rich or lean problems will be the HO2S in the manifold

• DTC P0053 HO2S Heater Resistance Bank 1 Sensor 1
The heated oxygen sensor (HO2S) must reach operating temperature to provide an accurate voltage signal. A heating element inside the HO2S minimizes the time required for the sensor to reach operating temperature. Voltage is provided to the heater by the ignition 1 voltage circuit through a fuse. With the engine running, ground is provided to the heater by the HO2S heater low control circuit, through a low side driver within the powertrain control module (PCM). The PCM commands the heater ON or OFF to maintain a specific HO2S operating temperature range. The PCM determines the temperature by measuring the current flow through the heater. When the heater is in the ON state, the PCM will pulse the heater OFF for a duration of 50 ms, once per second. When the heater is in the OFF state, the PCM will pulse the heater ON for a duration of 50 ms, once per second. The PCM calculates the heater resistance on a cold start. This diagnostic will only run once per ignition cycle. If the PCM detects that the heater calculated resistance is not within an expected range, DTC P0053 sets for HO2S bank 1 sensor 1, or DTC P0059 sets for HO2S bank 2 sensor 1.

Turn ON the ignition, with the engine OFF.
Command the HO2S heaters ON with a scan tool.
Wait 15 seconds to allow the HO2S heater current to stabilize.
Observe the affected HO2S heater current parameter with a scan tool.
Is the HO2S heater current parameter within the specified range?
0.25-3.125 A
Inspect the O2A fuse.
Is the O2A fuse open?

DTC P0135 HO2S Heater Performance Bank 1 Sensor 1

Conditions for Setting the DTC
• The PCM detects that the affected HO2S Heater current parameter is greater than 3.125 amps or less than 0.25 amps.
• The above condition is met for 10 seconds.

Could be the Heater inside is open or a fuse problem , check fuse first , if you have not already done so.
Bank 1 sensor 1 is located on left side of the engine in the exhaust pipe before crossover

catalytic converter .
In order to control emissions, a catalytic converter converts any harmful exhaust emissions into harmless water vapor and carbon dioxide.
The powertrain control module (PCM) has the capability to monitor this process by using a rear-heated oxygen sensor (HO2S 2). The HO2S 2 , located in the exhaust stream past the catalytic converter, produces an output signal which indicates the storage capacity of the catalyst. This in turn indicates the catalysts ability to convert the exhaust emissions effectively. If the catalyst is functioning properly, the HO2S 2 signal will be far less active than the signal produced by the front oxygen sensor (O2S 1).

code p 0038 refers to heated oxygen sensor (HO2S) 2 bank 1 heated control --circuit low===causes --wiring short to positive --- HO2S--- ecm
code p 0136 refers to HO2S 2 bank 1 circuit malfunction===causes --heating inoperative --wiring-- HO2S
it also refers to HO2S --no signal===causes ---wiring --HO2S
bank 1 is the bank closest to the fire wall and heated oxygen sensors(HO2S) are always in the exhaust manifold/pipe before the cat converter
the wires in the HO2S are delicate so always use the correct sensor socket for removal and installation of the sensors

Four .
Heated Oxygen Sensor (HO2S Bank 1 Position 1)
Located in RH front pipe of the exhaust catalytic converter
--
Engine Controls Connector End Views in Engine Controls
Heated Oxygen Sensor (HO2S Bank 1 Position 2)
Located in RH rear pipe of the exhaust catalytic converter
--
Engine Controls Connector End Views in Engine Controls
Heated Oxygen Sensor (HO2S Bank 2 Position 1)
Located in LH front pipe of the exhaust catalytic converter
--
Engine Controls Connector End Views in Engine Controls
Heated Oxygen Sensor (HO2S Bank 2 Position 2)
Located in LH rear pipe of the exhaust catalytic converter

CODE PO151 - HO2S - 21 BANK 2 SENSOR 1 CIRCUIT LOW INPUT. CODE PO153- HO2S BANK 2 SENSOR 1 CIRCUIT SLOW RESPONSE. CODE P1151 - LACK OF HO2S - 21 SWITCHING HO2S SIGNAL LOW INPUT. POSSIBLE CAUSES TO YOUR PROBLEM AIR INTAKE SYSTEM LEAKING VACUUM HOSES LEAKING OR DAMAGED.AIR LEAKS LOCATED AFTER THE MAF SENSOR MOUNTING LOCATION OR IN THE PCV SYSTEM. YOU COULD HAVE BASE MECHANICAL FAULT LIKE LOW CYLINDER COMPRESSION , VALVE TIMING OFF.HO2S CIRCUITS WET OR OILY CORRODED OR POOR TERMINAL CONTACT. HO2S SIGNAL CIRCUIT OPEN SHORTED TO GROUND SHORTED TO POWER OR THE SENSOR HAS FAILED. LOW FUEL PRESSURE OR VECHICLE DRIVEN UNTIL IT WAS OUT OF FUEL. BEFORE REPLACING PCM CHECK ALL VACUUM HOSES ON INTAKE MANIFOLD. REPLACE FUEL FILTER. CHECK YOUR SPARK PLUGS. IF SPARK PLUGS OIL COATED PROBLEM IN THE ENGINE ITSELF. YOU HAVE WORN PISTON RINGS, WORN VALVE GUIDES AND WORN VALVE SEALS. IF PCM WAS BAD YOU WOULD HAVE FLASHING CHECK ENGINE LIGHT CAR WOULD RUN POORLY.YOU WILL HAVE FAULT PCM CODE IF PCM FAILED. YOUR PROBLEM IN HO2S SENSORS AND THE ENGINE AIR FUEL MIXTURE.

Hi there,

P0030 = HO2S Heater Control Circuit (Bank 1 Sensor 1) - No.1 Heated Oxygen sensor on bank 1.
P0036 = HO2S Heater Control Circuit (Bank 1 Sensor 2) - No. 2 Heated Oxygen sensor on bank 1

For both of these to trigger on the same bank, means most likely an Open or Short to Ground condition (somewhere on the Bank 1 circuit) stopping the HO2 sensors from reaching their working temperature.

Check the following in this order:

1) Using a multimeter, check 'continuity' of the Oxygen circuit FUSE terminals (don't rely on visual inspection alone) or replace fuse with a known good one.
2) Check for moisture getting into both oxygen sensor connector terminals (bank 1).
3) Check for good connection at Oxygen sensors (bank 1).
3) Have both heated oxygen sensors on Bank 1 tested (ensure their values are to specification).
4) Check HO2 pin-outs of the PCM for correct voltage.

Only replace the HO2 sensors as a last resort (if out of spec).

Then engine department relay centre & fusebox location is behind the washer bottle, but I believe the HO2 sensors are connected direct to the PCM, not a relay.

Cheers,


"If this has helped you in any way, please rate this solution"

Fig. Component Location Chart-2000 MPV

1 PCM 2 Mass air flow (MAF)/intake air temperature (IAT) sensor 3 Throttle position (TP) sensor 4 Fuel tank pressure sensor 5 Engine coolant temperature (ECT) sensor 6 Crankshaft position (CKP) sensor 7 Camshaft position (CMP) sensor 8 Knock sensor 9 Heated oxygen sensor (HO2S) (front, LH) 10 Heated oxygen sensor (HO2S) (front, RH) 11 Heated oxygen sensor (HO2S) (rear, LH) 12 Heated oxygen sensor (HO2S) (rear, RH) 13 EGR boost sensor 14 Power steering pressure (PSP) switch 15 Main relay


Fig. Component Location Chart-2001 MPV

1 PCM 2 Mass air flow (MAF)/Intake air temperature (IAT) sensor 3 Throttle position (TP) sensor 4 Engine coolant temperature (ECT) sensor 5 Crankshaft position (CKP) sensor 6 Camshaft position (CMP) sensor 7 Knock sensor 8 Heated oxygen sensor (HO2S) (front, LH) 9 Heated oxygen sensor (HO2S) (front, RH) 10 Heated oxygen sensor (HO2S) (rear, LH)* 11 Heated oxygen sensor (HO2S) (rear, RH)* 12 EGR boost sensor


Fig. Component Location Chart- 2002-06 MPV

Fig. Heated Oxygen (HO2S) location (sensor 1)-2.4L engine



Fig. Heated Oxygen (HO2S) location (sensor 2)-2.4L engine



Fig. Heated Oxygen (HO2S) location (bank 1, sensor 2) (bank 2, sensor 2)-2.7L engine



Fig. Heated Oxygen (HO2S) location (bank 2, sensor 1)-2.7L engine

I hope help you with this (rated this help). Good luck.

DTC P0156 indicates the output voltage of the downstream Heated Oxygen Sensor (HO2S) is less than some calibratable functional window. The possible causes are:

1. Pinched, shorted and/or corroded wiring and pins.
2. Crossed sensor wires
3. Exhaust leaks.
4. Contaminated HO2S.
5. Bad HO2S.

Since you didnt specify the engine size in your vehicle - please see the diagram below for the location of the sensor(s)


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