What Does P1153 Mean?
This manufacturer-specific code indicates the air/fuel ratio (A/F) sensor on bank 2, sensor 1 (upstream of catalytic converter) is not responding within the expected parameters. The sensor's voltage switching rate or amplitude is outside the ECM's calibrated thresholds, meaning the PCM cannot accurately determine the exhaust oxygen content for that cylinder bank. This leads to degraded fuel trim control and potentially elevated emissions on bank 2.
Common Causes
35%
Failed or degraded air/fuel ratio sensor (wideband O2 sensor)
25%
Exhaust leak upstream of the A/F sensor on bank 2
20%
Damaged or corroded wiring/connector to the A/F sensor
12%
Fuel injector imbalance or misfire on bank 2 cylinders
8%
ECM internal circuit fault for A/F sensor driver
Diagnostic Steps
1
Monitor A/F sensor voltage and switching frequency on bank 2 sensor 1 using live data; compare response rate to bank 1 sensor 1.
2
Inspect the A/F sensor wiring harness and connector for chafing, corrosion, or rodent damage; check for proper 5-wire connections.
3
Check for exhaust leaks at the exhaust manifold, gaskets, and pipe connections on bank 2 using a smoke machine or propane enrichment test.
4
Command a fuel injector balance test on bank 2 cylinders to rule out individual injector faults causing skewed readings.
5
If wiring and exhaust integrity are confirmed, replace the bank 2 sensor 1 air/fuel ratio sensor with an OE-spec unit.
Estimated Repair Cost
$150 - $450
Parts + labor, varies by vehicle and location
This manufacturer-specific code indicates the air/fuel ratio (A/F) sensor on bank 2, sensor 1 (upstream of catalytic converter) is not responding within the expected parameters. The sensor's voltage switching rate or amplitude is outside the ECM's calibrated thresholds, meaning the PCM cannot accura...
The most common cause of P1153 (Air/Fuel Ratio Sensor Circuit Response Malfunction (Bank 2 Sensor 1)) is: Failed or degraded air/fuel ratio sensor (wideband O2 sensor)
Typical repair costs for P1153 range from $150 to $450, depending on the vehicle, location, and whether you do it yourself or go to a shop.
No immediate safety risk, but prolonged operation can cause catalyst damage from incorrect fuel mixture and may lead to increased emissions and reduced fuel economy.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to P1153 to identify the root cause.
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Quick Info
Category
Powertrain
System
Fuel / Air Metering
Difficulty
Type
Manufacturer
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