Toggle Side Panel

Shopping Cart

No products in the basket.

Shopping Cart

No products in the basket.

Close search
Home / DTC / P0145 — O2 Sensor Circuit Slow Response Bank 1 Sensor 3

P0145 — O2 Sensor Circuit Slow Response Bank 1 Sensor 3

Detailed page for trouble code P0145.

34,405codes
59brands
11,914generic
22,491specific
All codes P-codes (Powertrain) B-codes (Body) C-codes (Chassis) U-codes (Network/User) Tesla Alerts
Reset
Code

P0145

Generic P — Powertrain

O2 Sensor Circuit Slow Response Bank 1 Sensor 3

Brand: Generic
Type: P — Powertrain
AI status
Completed
ready
Completed 100%
Page language: EN

Causes

  • Aging or contaminated O2 sensor (sensor degradation)
  • Contaminants on sensing element (oil, coolant, silicone, fuel additives)
  • Damaged or corroded wiring or connectors in the sensor circuit
  • Poor sensor heater operation or slow warm-up
  • Exhaust leak upstream of the sensor
  • Faulty catalytic converter reducing expected oxygen change

Symptoms

  • Malfunction Indicator Lamp (MIL) illuminated
  • Possible failed emissions test
  • Reduced fuel economy (sometimes)
  • Possible rough idle or drivability issues (less common for downstream sensor codes)
  • Incomplete or failed catalyst monitoring readiness

What to check

  • Read and record freeze frame and related codes; note readiness status
  • Visual inspection of sensor wiring, connectors and harness for damage or corrosion
  • Check for exhaust leaks near sensor and upstream areas
  • Verify proper power/ground to sensor heater and signal circuit at connector
  • Compare sensor voltage/waveform to upstream sensor using a scan tool or oscilloscope
  • Measure heater resistance against manufacturer spec

Signal parameters

  • Narrowband O2 sensor typical voltage range: ~0.1–0.9 V (varies by vehicle)
  • Upstream (pre-cat) sensor should switch rapidly between low and high voltages during closed-loop
  • Downstream (post-cat) sensor often shows more stable voltage near mid-level when catalyst is good, but should still reflect changes with upstream; slow response means delayed or damped change compared with upstream
  • Heater circuit should show continuity and be powered to reach operating temperature quickly (exact resistance/voltage varies by manufacturer)

Diagnostic algorithm

  1. Confirm code and check for other related O2 or catalyst codes (note freeze frame).
  2. Perform a visual inspection: sensor, connector, wiring harness for damage, contamination, or corrosion; repair obvious issues.
  3. Check for exhaust leaks and repair if present.
  4. Backprobe sensor connector and verify heater power and ground with ignition on; measure heater resistance and compare to spec.
  5. Using a scan tool or lab scope, monitor Bank 1 Sensor 1 (upstream) and Bank 1 Sensor 3 signals simultaneously during warm idle and during commanded fuel changes. Look for delayed or muted response on Sensor 3 relative to Sensor 1.
  6. If sensor heater is not functioning or sensor signal is out of expected range, replace the sensor. If wiring/power/ground problems are found, repair wiring and retest.
  7. If sensor and wiring check good but downstream response remains abnormal, inspect catalytic converter efficiency (temperature probes, backpressure, or downstream vs upstream readings); replace catalyst if confirmed failing.
  8. Clear codes and perform drive cycle to verify repair and readiness.

Likely causes

  • Failed or aged downstream oxygen sensor
  • Open/short or high resistance in signal/ground wiring or connector
  • Heater circuit not reaching operating temperature
  • Exhaust leak near upstream sensor or near sensor mounting
  • Catalyst inefficiency or internal damage

Fault status

⚠️ Status
O2 Sensor Circuit Slow Response — Bank 1 Sensor 3. The downstream oxygen sensor is not responding at the expected rate, indicating a slow or delayed signal.
🟡 Repair difficulty: Medium
⏱️ Diagnostic time: 0.5-2.5 hours

Similar codes

P0139 P0140 P0138 P0135 P0420
8,037

The library contains 8,037 repair and diagnostic manuals. Choose a brand to open the full manual tree by year, model and trim.

ALFA ROMEO
89
AUDI
1,160
BMW
479
CHEVROLET
355
DAEWOO
75
FIAT
26
GENESIS
207
HUMMER
138
HYUNDAI
371
ISUZU
86
LAND ROVER
320
LEXUS
280
LINCOLN
166
MERCEDES-BENZ
856
MERCURY
296
MITSUBISHI
406
PORSCHE
136
TESLA
58
TOYOTA
2,042
TRIUMPH
131
VOLKSWAGEN
139
VOLVO
221
Your experience will help others
+100 karma for a short comment :)
Keep it short and practical. Up to 500 characters.
Send to email
Code

P0145

GWM P — Powertrain

- The oxygen sensor responds late (bank 1, sensor 3)

Brand: GWM
Type: P — Powertrain
AI status
Completed
ready
Completed 100%
Page language: EN

Causes

  • Aging or contaminated O2 sensor (sensor degradation)
  • Contaminants on sensing element (oil, coolant, silicone, fuel additives)
  • Damaged or corroded wiring or connectors in the sensor circuit
  • Poor sensor heater operation or slow warm-up
  • Exhaust leak upstream of the sensor
  • Faulty catalytic converter reducing expected oxygen change

Symptoms

  • Malfunction Indicator Lamp (MIL) illuminated
  • Possible failed emissions test
  • Reduced fuel economy (sometimes)
  • Possible rough idle or drivability issues (less common for downstream sensor codes)
  • Incomplete or failed catalyst monitoring readiness

What to check

  • Read and record freeze frame and related codes; note readiness status
  • Visual inspection of sensor wiring, connectors and harness for damage or corrosion
  • Check for exhaust leaks near sensor and upstream areas
  • Verify proper power/ground to sensor heater and signal circuit at connector
  • Compare sensor voltage/waveform to upstream sensor using a scan tool or oscilloscope
  • Measure heater resistance against manufacturer spec

Signal parameters

  • Narrowband O2 sensor typical voltage range: ~0.1–0.9 V (varies by vehicle)
  • Upstream (pre-cat) sensor should switch rapidly between low and high voltages during closed-loop
  • Downstream (post-cat) sensor often shows more stable voltage near mid-level when catalyst is good, but should still reflect changes with upstream; slow response means delayed or damped change compared with upstream
  • Heater circuit should show continuity and be powered to reach operating temperature quickly (exact resistance/voltage varies by manufacturer)

Diagnostic algorithm

  1. Confirm code and check for other related O2 or catalyst codes (note freeze frame).
  2. Perform a visual inspection: sensor, connector, wiring harness for damage, contamination, or corrosion; repair obvious issues.
  3. Check for exhaust leaks and repair if present.
  4. Backprobe sensor connector and verify heater power and ground with ignition on; measure heater resistance and compare to spec.
  5. Using a scan tool or lab scope, monitor Bank 1 Sensor 1 (upstream) and Bank 1 Sensor 3 signals simultaneously during warm idle and during commanded fuel changes. Look for delayed or muted response on Sensor 3 relative to Sensor 1.
  6. If sensor heater is not functioning or sensor signal is out of expected range, replace the sensor. If wiring/power/ground problems are found, repair wiring and retest.
  7. If sensor and wiring check good but downstream response remains abnormal, inspect catalytic converter efficiency (temperature probes, backpressure, or downstream vs upstream readings); replace catalyst if confirmed failing.
  8. Clear codes and perform drive cycle to verify repair and readiness.

Likely causes

  • Failed or aged downstream oxygen sensor
  • Open/short or high resistance in signal/ground wiring or connector
  • Heater circuit not reaching operating temperature
  • Exhaust leak near upstream sensor or near sensor mounting
  • Catalyst inefficiency or internal damage

Fault status

⚠️ Status
O2 Sensor Circuit Slow Response — Bank 1 Sensor 3. The downstream oxygen sensor is not responding at the expected rate, indicating a slow or delayed signal.
🟡 Repair difficulty: Medium
⏱️ Diagnostic time: 0.5-2.5 hours

Similar codes

P0139 P0140 P0138 P0135 P0420
Your experience will help others
+100 karma for a short comment :)
Keep it short and practical. Up to 500 characters.
Send to email
Code

P0145

HUMMER P — Powertrain

Heated Oxygen Sensor (HO2S) Circuit Bank 1 Sensor 2 Slow Response

Brand: HUMMER
Type: P — Powertrain
AI status
Completed
ready
Completed 100%
Page language: EN

Causes

  • Aging or contaminated O2 sensor (sensor degradation)
  • Contaminants on sensing element (oil, coolant, silicone, fuel additives)
  • Damaged or corroded wiring or connectors in the sensor circuit
  • Poor sensor heater operation or slow warm-up
  • Exhaust leak upstream of the sensor
  • Faulty catalytic converter reducing expected oxygen change

Symptoms

  • Malfunction Indicator Lamp (MIL) illuminated
  • Possible failed emissions test
  • Reduced fuel economy (sometimes)
  • Possible rough idle or drivability issues (less common for downstream sensor codes)
  • Incomplete or failed catalyst monitoring readiness

What to check

  • Read and record freeze frame and related codes; note readiness status
  • Visual inspection of sensor wiring, connectors and harness for damage or corrosion
  • Check for exhaust leaks near sensor and upstream areas
  • Verify proper power/ground to sensor heater and signal circuit at connector
  • Compare sensor voltage/waveform to upstream sensor using a scan tool or oscilloscope
  • Measure heater resistance against manufacturer spec

Signal parameters

  • Narrowband O2 sensor typical voltage range: ~0.1–0.9 V (varies by vehicle)
  • Upstream (pre-cat) sensor should switch rapidly between low and high voltages during closed-loop
  • Downstream (post-cat) sensor often shows more stable voltage near mid-level when catalyst is good, but should still reflect changes with upstream; slow response means delayed or damped change compared with upstream
  • Heater circuit should show continuity and be powered to reach operating temperature quickly (exact resistance/voltage varies by manufacturer)

Diagnostic algorithm

  1. Confirm code and check for other related O2 or catalyst codes (note freeze frame).
  2. Perform a visual inspection: sensor, connector, wiring harness for damage, contamination, or corrosion; repair obvious issues.
  3. Check for exhaust leaks and repair if present.
  4. Backprobe sensor connector and verify heater power and ground with ignition on; measure heater resistance and compare to spec.
  5. Using a scan tool or lab scope, monitor Bank 1 Sensor 1 (upstream) and Bank 1 Sensor 3 signals simultaneously during warm idle and during commanded fuel changes. Look for delayed or muted response on Sensor 3 relative to Sensor 1.
  6. If sensor heater is not functioning or sensor signal is out of expected range, replace the sensor. If wiring/power/ground problems are found, repair wiring and retest.
  7. If sensor and wiring check good but downstream response remains abnormal, inspect catalytic converter efficiency (temperature probes, backpressure, or downstream vs upstream readings); replace catalyst if confirmed failing.
  8. Clear codes and perform drive cycle to verify repair and readiness.

Likely causes

  • Failed or aged downstream oxygen sensor
  • Open/short or high resistance in signal/ground wiring or connector
  • Heater circuit not reaching operating temperature
  • Exhaust leak near upstream sensor or near sensor mounting
  • Catalyst inefficiency or internal damage

Fault status

⚠️ Status
O2 Sensor Circuit Slow Response — Bank 1 Sensor 3. The downstream oxygen sensor is not responding at the expected rate, indicating a slow or delayed signal.
🟡 Repair difficulty: Medium
⏱️ Diagnostic time: 0.5-2.5 hours

Similar codes

P0139 P0140 P0138 P0135 P0420
Repair manuals

Manual library for HUMMER

138

Browse 138 HUMMER manuals: repair procedures, diagnostics, wiring diagrams, component locations, service data and Labor Times by year, model and trim.

HUMMER

Your experience will help others
+100 karma for a short comment :)
Keep it short and practical. Up to 500 characters.
Send to email
Code

P0145

LAND ROVER P — Powertrain

Oxygen sensor - slow response circuit. Bank 1 - sensor 3

Brand: LAND ROVER
Type: P — Powertrain
AI status
Completed
ready
Completed 100%
Page language: EN

Causes

  • Aging or contaminated O2 sensor (sensor degradation)
  • Contaminants on sensing element (oil, coolant, silicone, fuel additives)
  • Damaged or corroded wiring or connectors in the sensor circuit
  • Poor sensor heater operation or slow warm-up
  • Exhaust leak upstream of the sensor
  • Faulty catalytic converter reducing expected oxygen change

Symptoms

  • Malfunction Indicator Lamp (MIL) illuminated
  • Possible failed emissions test
  • Reduced fuel economy (sometimes)
  • Possible rough idle or drivability issues (less common for downstream sensor codes)
  • Incomplete or failed catalyst monitoring readiness

What to check

  • Read and record freeze frame and related codes; note readiness status
  • Visual inspection of sensor wiring, connectors and harness for damage or corrosion
  • Check for exhaust leaks near sensor and upstream areas
  • Verify proper power/ground to sensor heater and signal circuit at connector
  • Compare sensor voltage/waveform to upstream sensor using a scan tool or oscilloscope
  • Measure heater resistance against manufacturer spec

Signal parameters

  • Narrowband O2 sensor typical voltage range: ~0.1–0.9 V (varies by vehicle)
  • Upstream (pre-cat) sensor should switch rapidly between low and high voltages during closed-loop
  • Downstream (post-cat) sensor often shows more stable voltage near mid-level when catalyst is good, but should still reflect changes with upstream; slow response means delayed or damped change compared with upstream
  • Heater circuit should show continuity and be powered to reach operating temperature quickly (exact resistance/voltage varies by manufacturer)

Diagnostic algorithm

  1. Confirm code and check for other related O2 or catalyst codes (note freeze frame).
  2. Perform a visual inspection: sensor, connector, wiring harness for damage, contamination, or corrosion; repair obvious issues.
  3. Check for exhaust leaks and repair if present.
  4. Backprobe sensor connector and verify heater power and ground with ignition on; measure heater resistance and compare to spec.
  5. Using a scan tool or lab scope, monitor Bank 1 Sensor 1 (upstream) and Bank 1 Sensor 3 signals simultaneously during warm idle and during commanded fuel changes. Look for delayed or muted response on Sensor 3 relative to Sensor 1.
  6. If sensor heater is not functioning or sensor signal is out of expected range, replace the sensor. If wiring/power/ground problems are found, repair wiring and retest.
  7. If sensor and wiring check good but downstream response remains abnormal, inspect catalytic converter efficiency (temperature probes, backpressure, or downstream vs upstream readings); replace catalyst if confirmed failing.
  8. Clear codes and perform drive cycle to verify repair and readiness.

Likely causes

  • Failed or aged downstream oxygen sensor
  • Open/short or high resistance in signal/ground wiring or connector
  • Heater circuit not reaching operating temperature
  • Exhaust leak near upstream sensor or near sensor mounting
  • Catalyst inefficiency or internal damage

Fault status

⚠️ Status
O2 Sensor Circuit Slow Response — Bank 1 Sensor 3. The downstream oxygen sensor is not responding at the expected rate, indicating a slow or delayed signal.
🟡 Repair difficulty: Medium
⏱️ Diagnostic time: 0.5-2.5 hours

Similar codes

P0139 P0140 P0138 P0135 P0420
320

Browse 320 LAND ROVER manuals: repair procedures, diagnostics, wiring diagrams, component locations, service data and Labor Times by year, model and trim.

LAND ROVER

Your experience will help others
+100 karma for a short comment :)
Keep it short and practical. Up to 500 characters.
Send to email

Report

Harassment or bullying behavior
Contains mature or sensitive content
Contains misleading or false information
Contains abusive or derogatory content
Contains spam, fake content or potential malware

Block Member?

Please confirm you want to block this member.

You will no longer be able to:

  • See blocked member's posts
  • Mention this member in posts
  • Invite this member to groups
  • Message this member
  • Add this member as a connection

Please note: This action will also remove this member from your connections and send a report to the site admin. Please allow a few minutes for this process to complete.

Report

You have already reported this .