Fix P0153: Mechanic’s solutions that WORKED

The code P0153: O2 Sensor Circuit Slow Response (Bank 2 Sensor 1) indicates a fault in the oxygen sensor’s response time, specifically in Bank 2 Sensor 1. This issue is most likely caused by a malfunctioning O2 sensor or an exhaust leak affecting the sensor’s readings.

P0153 quick overview

Meaning	P0153: O2 Sensor Circuit Slow Response (Bank 2 Sensor 1)
Is it serious?	Yes, it can affect the vehicle’s fuel efficiency and emissions.
Possible causes	– Faulty or slow-responding O2 sensor – Exhaust leaks near the O2 sensor – Leaking fuel pressure regulator – Faulty fuel injectors – Wiring or connector issues – PCM software needing an update
How to diagnose?	Inspect the O2 Sensor: Check the response time and voltage to ensure it’s functioning correctly. Check for Exhaust Leaks: Perform a smoke test or visual inspection for any leaks that could affect O2 sensor readings. Evaluate Fuel Pressure Regulator: Inspect for any signs of leaking, especially at the vacuum line. Assess Fuel Injectors: Conduct a leak down test or look for signs of injectors bleeding down or being stuck open. Examine Wiring and Connectors: Look for any signs of damage, corrosion, or water intrusion. Monitor Fuel Trim Values: Check the readings to diagnose potential issues with fuel delivery or air intake. Check for Software Updates: Contact the manufacturer or check for technical service bulletins (TSBs) for any known software issues.

Code P0153 means that the oxygen sensor on the second bank of the engine is not responding as quickly as it should. This can make your car run less efficiently and pollute more. It’s often caused by a problem with the sensor itself or a leak in the exhaust near the sensor.

How to fix P0153 – learn from mechanics

I looked into P0153 service cases at iatn.com website where in the private forums the mechanics seek advice from other mechanics. I looked up a bunch of cases to help you decide how to fix your issue and see what would a real mechanic do to solve it.

Case #1: Ford

Vehicle Information
1997 Ford F-250 Lariat 4.6L

Issue + Repair History

• MIL Lamp on with code PO153 indicating slow response from O2 sensor.
• O2 sensor checked 4 times and seemed okay, technician hesitant to replace without certainty.

What Are People Suggesting to Fix Issue

• Suggestions from the community were not included in the provided text.

What Was the Final Fix

• Replaced all four O2 sensors to resolve the issue.

Case #2: Oldsmobile

Vehicle Information
1996 Oldsmobile Aurora 4.0L

Issue + Repair History

• MIL Lamp on, starts hard after sitting for more than ten minutes.
• Long cranks before starting, usually after three 5-second crank sessions.
• Fuel pressure consistent at 45 psi during cranking.
• ECT and IAT differences checked and found to be okay.
• Codes PO717 and PO153 present, PO717 hasn’t returned but PO153 is back.

Other OBD2 Codes + Test Results

• PO717: Input speed sensor circuit no signal
• PO153: Slow response bank 2 sensor 1

What Are People Suggesting to Fix Issue

• Check fuel pressure regulator for possible leaking diaphragm.
• Test for possible fuel injector stuck open flooding cylinder.
• Inspect the vacuum hose to the regulator for fuel leakage.
• Check fuel pressure after shutdown to see if it holds.
• Consider a leaking fuel pressure regulator or a bad input speed sensor in the transmission.

What Was the Final Fix

• Replaced the fuel pressure regulator, which resolved the long start issue.

Case #3: Chevrolet

Vehicle Information
1996 Chevrolet Blazer 4.3L

Issue + Repair History

• MIL Lamp on without clearing the code.
• Recorded freeze frame and observed slower cross counts of the right bank sensor compared to the left bank sensor.
• Code PO153 present in history.

What Are People Suggesting to Fix Issue

• Conduct further tests on the O2 sensor before condemning it.
• Use a lab scope to test the sensor signal wire.
• Add propane to test the sensor’s response time from lean to rich.
• Check for water intrusion in the harness as per a bulletin.

What Was the Final Fix

• Replaced the right bank sensor #1 (O2 sensor) which resolved the issue.
• Cleared the code and drove the vehicle until it passed the tests for code PO153.

Case #4: Chrysler

Vehicle Information
2005 Chrysler Sebring Limited 2.7L

Issue + Repair History

• MIL Lamp on repeatedly.
• Persistent code P0153 for O2 sensor 2/1 slow response.
• Multiple replacements of the sensor (aftermarket and OEM) without success.
• Circuitry testing performed with specific voltage readings on signal and return wires.
• Resistance checks on wires showed no faults.
• Considering condemning the PCM due to voltage discrepancies.

What Are People Suggesting to Fix Issue

• Check reference voltage at PCM with O2 sensor disconnected and connected to rule out wiring issues.
• Perform a smoke test on the exhaust system to check for leaks.
• Look for any technical service bulletins (TSBs) for a software update.

What Was the Final Fix

• Smoke tested the exhaust system and found a small leak at the fitting post-cat nearest to 2/2 O2 sensor.
• Adjusted the fitting and re-tightened bolts/nuts.
• Cleared codes and drove the vehicle until the monitor reset. The code did not return.

Case #5: Suzuki

Vehicle Information
2004 Suzuki Verona EX 2.5L

Issue + Repair History

• MIL Lamp on with codes P0133 and P0153.
• Replaced both upstream O2 sensors and PCV valve.
• Stalling on deceleration issue fixed by replacing throttle body assembly.
• Codes P0133 and P0153 persist.
• Voltage measurements and fuel trim readings within normal range.

What Are People Suggesting to Fix Issue

• Check exhaust gas readings and engine vacuum.
• Test O2 sensor response to rich/lean conditions.
• Look for exhaust leaks around O2 sensors.
• Check for correct wiring of O2 sensors.
• Consider ECM reflash for false slow O2 sensor DTCs.

What Was the Final Fix

• Contacted Suzuki and learned of a PCM flash for false P0133 and P0153 codes.
• Performed the update and returned the vehicle to the customer after a successful 30-mile test drive.

Advice	Description of Diagnostic Step
Check Fuel Pressure Regulator	Inspect for leaks, especially at the vacuum line, which could indicate a diaphragm issue.
Inspect O2 Sensors	Verify the response time and voltage of O2 sensors to ensure they are functioning within specified parameters.
Look for Exhaust Leaks	Perform a smoke test or visual inspection to identify any leaks that could affect O2 sensor readings.
Consider Injector Issues	Perform a leak down test or inspect for signs of injector bleeding down or being stuck open.
Check for Software Updates/Reflashes	Contact the manufacturer or check for technical service bulletins (TSBs) for any known software issues.
Evaluate Wiring and Connectors	Inspect the wiring harness and connectors for signs of damage, corrosion, or water intrusion.
Monitor Fuel Trim Values	Check the fuel trim readings to diagnose potential issues with fuel delivery or air intake.