SheckyB

PO171 Code 2007 HHR Did smoke test No leak Any Suggestions??

donbrew

What smoke test? Vacuum leaks don't come from EVAP leaks. The vac leaks referenced are after the EVAP purge valve, or the EVAP purge valve stuck open (hard starting typically). Basically between the MAF and the #1 O2 sensor.
Check:
fuel pressure.
PCV hose.
flex pipe
brake booster hose
clean the MAF

SheckyB

Trying to be a Youtube Mechanic.......Now my light went back on telling me my 02 sensor has no activity May I ask Does it matter if I pay 20 dollars or 80 for a 02 sensor??

donbrew

What code? From your description it could be any one of 11 different codes.

If you are certain that you want to take you scanner's advice I would stay away from Bosch and get NTK/NGK. But I would look at wires and fuses and flex pipe first.

Oldblue

If it’s P0171 again, have a through read!


https://www.obd-codes.com/p0171

clean your MAF sensor first , then check the flex pipe for broken billows

SheckyB

Just Changed Cat and 02 Sensors a month ago Was Getting PO171 I bought the Gadget to Erase Codes Now Don't see PO171 anymore Now Its P2A01 And P2A00 Going Nuts With The Check Engine Light Can't seem to Keep it Off every time I fix something Next problem occurs Any Suggestions??

DrLoch

Those are both O2 Sensor related. DId you change both, what brand of sensors did you get? AC Delco are the only ones that I have found to work correctly on GM cars. Next question, where did you get the cat?

DrLoch

Long things to check

DTC P0133, P0134, P0140, P1133, P2A00 or P2A01

Diagnostic Instructions

• Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. See: Testing and Inspection\Initial Inspection and Diagnostic Overview
• Review Strategy Based Diagnosis for an overview of the diagnostic approach.
• Diagnostic Procedure Instructions provides an overview of each diagnostic category.

DTC Descriptors
DTC P0133

• HO2S Slow Response Sensor 1

DTC P0134

• HO2S Circuit Insufficient Activity Sensor 1

DTC P0140

• HO2S Circuit Insufficient Activity Sensor 2

DTC P1133

• HO2S Insufficient Switching Sensor 1

DTC P2A00

• HO2S Circuit Closed Loop (CL) Performance Sensor 1

DTC P2A01

• HO2S Circuit Sensor 2

Diagnostic Fault Information





Typical Scan Tool Data



Circuit/System Description

Heated oxygen sensors (HO2S) are used for fuel control and post catalyst monitoring. Each HO2S compares the oxygen content of the surrounding air with the oxygen content in the exhaust stream. The HO2S must reach operating temperature to provide an accurate voltage signal. Heating elements inside the HO2S minimize the time required for the sensors to reach operating temperature. The engine control module (ECM) supplies the HO2S with a reference, or bias, voltage of about 450 mV . When the engine is first started, the ECM operates in Open Loop, ignoring the HO2S voltage signal. Once the HO2S reaches operating temperature and Closed Loop is achieved, the HO2S generates a voltage within a range of 0-1,000 mV that fluctuates above and below bias voltage. High HO2S voltage indicates a rich exhaust stream. Low HO2S voltage indicates a lean exhaust stream.

Conditions for Running the DTC

P0133

• DTCs P0068, P0101, P0102, P0103, P0106, P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0120, P0121, P0122, P0123, P0128, P0201, P0202, P0203, P0204, P0220, P0222, P0223, P0442, P0443, P0446, P0449, P0455, P0496, P1516, P2101, P2119, P2135, P2176 are not set.
• The Engine Coolant Temperature (ECT) Sensor parameter is more than 70°C (158°F) .
• The Ignition 1 Signal parameter is between 10-18 volts .
• The Fuel Level Sensor parameter is more than 10 percent .
• The Engine Run Time parameter is more than 200 seconds .
• The Engine Speed parameter is between 1,000-3,500 RPM .
• The Manifold Absolute Pressure (MAP) Sensor parameter is more than 30 kPa .
• The Mass Airflow (MAF) Sensor parameter is between 11-50 g/s .
• The Loop Status parameter is Closed.
• The Throttle Position (TP) Indicated Angle parameter is more than 5 percent .
• DTC P0133 runs once per drive cycle when the above conditions are met for 2 seconds .

P0134

• DTCs P0068, P0101, P0102, P0103, P0106, P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0120, P0121, P0122, P0123, P0128, P0201, P0202, P0203, P0204, P0220, P0222, P0223, P0442, P0443, P0446, P0449, P0455, P0496, P1516, P2101, P2119, P2135, P2176 are not set.
• The Engine Coolant Temperature (ECT) Sensor parameter is more than 70°C (158°F) .
• The Ignition 1 Signal parameter is between 10-18 volts .
• The engine run time is more than 200 seconds .
• DTC P0134 runs continuously when the above conditions are met.

P0140

• DTCs P0068, P0101, P0102, P0103, P0106, P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0120, P0121, P0122, P0123, P0128, P0201, P0202, P0203, P0204, P0220, P0222, P0223, P0442, P0443, P0446, P0449, P0455, P0496, P1516, P2101, P2119, P2135, P2176 are not set.
• The ECT Sensor parameter is more than 70°C (158°F) .
• The Ignition 1 Signal parameter is between 10-18 volts .
• The Engine Run Time parameter is more than 200 seconds .
• The Loop Status parameter is closed.
• DTC P0140 runs once per drive cycle when the above conditions are met.

P1133

• DTCs P0068, P0101, P0102, P0103, P0106, P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0120, P0121, P0122, P0123, P0128, P0201, P0202, P0203, P0204, P0220, P0222, P0223, P0442, P0443, P0446, P0449, P0455, P0496, P1516, P2101, P2119, P2135, P2176 are not set.
• The ECT Sensor parameter is more than 70°C (158°F) .
• The Engine Speed parameter is between 1,500-3,500 RPM .
• The Ignition 1 Signal parameter is between 10-18 volts .
• The Engine Run Time parameter is more than 200 seconds .
• The Loop Status parameter is Closed.
• The TP Indicated Angle parameter is more than 5 percent .
• The Fuel Level Sensor parameter is more than 10 percent .
• The MAP Sensor parameter is more than 30 kPa .
• The MAF Sensor parameter is between 11-50 g/s .
• DTC P1133 runs once per drive cycle when the above conditions are met for 2 seconds .

DrLoch

P2A00

• DTCs P0068, P0101, P0102, P0103, P0106, P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0120, P0121, P0122, P0123, P0128, P0201, P0202, P0203, P0204, P0220, P0222, P0223, P0442, P0443, P0446, P0449, P0455, P0496, P1516, P2101, P2119, P2135, P2176 are not set.
• The Engine Run Time parameter is more than 100 seconds .
• The Engine speed parameter is between 1,000-3,400 RPM .
• The Ignition 1 Signal parameter is between 10-18 volts .
• The Mass Airflow (MAF) Sensor parameter is between 10-30 g/s .
• The ECT Sensor parameter is more than 70°C (158°F) .
• DTC P2A00 runs continuously when the above conditions are met for 5 seconds .

P2A01 Passive Test

• DTCs P0030, P0036, P0053, P0054, P0068, P0101, P0102, P0103, P0106, P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0120, P0121, P0122, P0123, P0128, P0131, P0132, P0133, P0134, P0135, P0137, P0138, P0140, P0141, P0201, P0202, P0203, P0204, P0220, P0222, P0223, P0442, P0443, P0446, P0449, P0455, P0496, P1133, P1516, P2101, P2119, P2135, P2176, P2A00 are not set.
• The engine is running.
• The Engine Run Time parameter is less than 13.3 minutes .
• DTC P2A01 runs the passive test once per drive cycle when the above conditions are met.

P2A01 Intrusive Test

• DTCs P0030, P0036, P0053, P0054, P0068, P0101, P0102, P0103, P0106, P0107, P0108, P0112, P0113, P0116, P0117, P0118, P0120, P0121, P0122, P0123, P0128, P0131, P0132, P0133, P0134, P0135, P0137, P0138, P0140, P0141, P0201, P0202, P0203, P0204, P0220, P0222, P0223, P0442, P0443, P0446, P0449, P0455, P0496, P1133, P1516, P2101, P2119, P2135, P2176, P2A00 are not set.
• The Engine Run Time parameter is more than 13.3 minutes .
• The ignition 1 Signal parameter is between 10-18 volts .
• The MAF sensor parameter is between 14-100 g/s .
• The Engine Speed parameter is between 1,000-5,000 RPM.
• The Vehicle Speed parameter is between 32-129 km/h (20-80 mph) .
• The Short Term FT parameter is between -20 and +20 percent .
• The maximum number of intrusive attempts is less than 50.
• DTC P2A01 runs the intrusive test once per drive cycle when the above conditions are met for 1 second .

Conditions for Setting the DTC

P0133

• The ECM detects that the HO2S 1 rich-to-lean or lean-to-rich average response time is more than 0.1 second .
• DTC P0133 sets within 60 seconds when the above condition is met.

P0134

• The ECM detects that the HO2S 1 parameter is between 400-500 mV for 100 seconds .
• The Throttle Position (TP) Indicated Angle parameter changes more than 1 percent , 3 times.
• DTC P0134 sets within 100 seconds when the above conditions are met.

P0140

• The ECM detects that the HO2S 2 parameter is between 425-475 mV .
• The TP Indicated Angle parameter changes more than 1 percent 3 times.
• DTC P0140 sets within 100 seconds when the above conditions are met.

P1133

• The ECM detects that the HO2S 1 rich-to-lean counts, or the lean-to-rich counts are less than a calibrated value.
• DTC P1133 sets within 60 seconds when the above condition is met.

P2A00

• The ECM detects that the Loop Status parameter is open.
• DTC P2A00 sets within 50 seconds when the above condition is met.

P2A01

1. The ECM detects that the HO2S 2 did not transition below 300 mV and above 700 mV during the passive test.
2. One of the following tests fail:

Lean Intrusive Test

• The ECM detects that the HO2S 2 is more than 300 mV for 12 seconds .
• The HO2S 1 is less than 350 mV .

Rich Intrusive Test

• The ECM detects that the HO2S 2 is less than 700 mV for 12 seconds .
• The HO2S 1 is more than 600 mV .

1. DTC P2A01 sets within 7 minutes when the above conditions are met.

Action Taken When the DTC Sets

DTC P0133, P0134, P0140, P1133, P2A00, P2A01 are Type B DTCs.

Conditions for Clearing the MIL/DTC

DTC P0133, P0134, P0140, P1133, P2A00, P2A01 are Type B DTCs.

Circuit/System Verification

• If any HO2S heater DTCs are set, perform those diagnostics first.
• Allow the engine to reach operating temperature.
• Engine running, observe the affected HO2S parameter with a scan tool.
• The pre-catalyst oxygen sensors value should vary from below 200 mV to above 800 mV and respond to fueling changes.
• The post-catalyst oxygen sensors value should change more than 200 mV when the throttle is quickly cycled 3 times from closed to wide open and back to closed after running the engine at 1,500 RPM for 30 seconds .
• The affected HO2S may be damaged due to contamination. Prior to replacing the affected HO2S, inspect for the following sources of contamination:

Notice: Refer to Silicon Contamination of Heated Oxygen Sensors Notice.

• A silicon contaminated HO2S
• Fuel contamination-Refer to Alcohol/Contaminants-in-Fuel Diagnosis. See: Powertrain Management\Computers and Control Systems\Testing and Inspection\Component Tests and General Diagnostics\Alcohol/Contaminants-in-Fuel Diagnosis
• Engine oil consumption-Refer to Oil Consumption Diagnosis. See: Engine, Cooling and Exhaust\Engine\Testing and Inspection\Component Tests and General Diagnostics
• Engine coolant consumption-Refer to Loss of Coolant. See: Engine, Cooling and Exhaust\Cooling System\Testing and Inspection\Symptom Related Diagnostic Procedures\Loss of Coolant

Circuit/System Testing

Important: All modules must be powered down or misdiagnosis may result.

1. Ignition OFF, disconnect the scan tool and wait 60 seconds to ensure all modules are powered down.
2. Ignition OFF, disconnect the harness connector at the appropriate HO2S.
3. Ignition OFF, measure for less than 5 ohms resistance between the appropriate HO2S low signal circuit terminal A and ground.

¤If more than the specified range, test the appropriate HO2S low signal circuit for an open/high resistance. If the circuit tests normal, replace the ECM.

1. Ignition ON, verify the appropriate scan tool HO2S parameter is approximately 450 mV .

¤If more than the specified value, test the appropriate HO2S high signal circuit for a short to voltage. If the circuit tests normal, replace the ECM.

¤If less than the specified value, test the appropriate HO2S high signal circuit for a short to ground. If the circuit tests normal, replace the ECM.

1. Ignition ON, install a 3A fused jumper wire at the HO2S high signal circuit terminal B. Toggle the jumper wire between the HO2S low signal circuit terminal A and battery voltage. Verify the appropriate scan tool HO2S parameter toggles between 0 mV and approximately 1,000 mV .

¤If the appropriate scan tool HO2S parameter does not toggle correctly, test the HO2S high signal circuit for an open/high resistance. If the circuits test normal, replace the ECM.

1. If all circuits test normal, replace the appropriate HO2S.

Repair Instructions

Notice: Refer to Heated Oxygen Sensor Resistance Learn Reset Notice.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure. See: Verification Tests

• Heated Oxygen Sensor 1 Replacement
• Heated Oxygen Sensor 2 Replacement
• Control Module References for replacement, setup, and programming See: Testing and Inspection\Programming and Relearning

donbrew

Check the wires to the sensors and the EXH fuse.