# P0153: O2 Sensor Circuit Slow Response (Bank 2 Sensor 1) **Verdict:** Safe to drive Oxygen sensors - Generic OBD-II code, applies to all gasoline cars and light trucks sold in the US since 1996. - **Typical cost:** $150-$550 - **Urgency:** Keep driving - **Most likely:** Aging upstream O2 sensor on bank 2 - **DIY?:** Yes, if reachable ## Quick answer P0153 means the upstream oxygen sensor on bank 2 is reacting too slowly when the fuel mixture changes. The engine computer relies on that sensor to fine-tune fuel for half of a V6 or V8, so a lazy sensor can cost fuel economy over time. An aging sensor is the usual cause, but an exhaust leak or contamination can produce the same result. ## What does P0153 mean? The upstream oxygen sensor on bank 2 sits in the exhaust manifold or front pipe on the side of the engine that does not have cylinder 1. It only exists on engines with two cylinder banks, such as V6, V8 and flat engines. The engine computer reads it many times a second and adds or removes fuel for that bank based on whether the exhaust looks rich or lean. A healthy narrow-band sensor swings between about 0.1 and 0.9 volt several times a second at steady cruise. P0153 sets when the computer times that swing and finds it too slow, or counts too few switches during its test window. The check usually runs on a fully warm engine at steady speed, and some makers briefly force the mixture rich and lean to time the reaction. Most cars need the slow result on two drive cycles before the light comes on. Sensor 1 means the sensor ahead of the catalytic converter, the one that controls fueling. ## What are the symptoms of P0153? - Check engine light on, car usually drives normally - Fuel economy slowly getting worse - Slightly rough or uneven idle on some engines - Failed emissions test or monitors that will not complete - Stronger exhaust smell than usual on a cold start ## What causes P0153? Ranked from most to least likely. Check them in this order: the cheap, common causes first. 1. **Worn-out upstream oxygen sensor on bank 2** (most common). Oxygen sensors slow down with age as deposits build on the sensing element. Upstream sensors run hotter than downstream ones, so they tend to wear first, often somewhere past 100,000 miles. On a scan tool, the bank 2 sensor switches noticeably slower than the bank 1 sensor, which is a useful side-by-side comparison on V6 and V8 engines. 2. **Exhaust leak ahead of the sensor** (common). A cracked manifold, leaking manifold gasket or broken stud on bank 2 lets outside air mix with the exhaust before it reaches the sensor. The extra oxygen blurs the rich and lean swings the sensor should see, so it looks slow. Leaks often tick on a cold start and quiet down as the metal warms and expands. 3. **Sensor contaminated by oil, coolant or sealant** (less common). Burning oil, a leaking head gasket or a silicone sealant that is not sensor-safe can coat the sensor tip with a glassy or chalky layer. The sensor then reacts sluggishly even if it is fairly new. If the bank 2 sensor fails again soon after replacement, look for oil or coolant entering that bank before fitting another. 4. **Fuel or air problem on bank 2** (less common). A vacuum leak, weak injector or misfire on bank 2 can keep that bank running lean or uneven, so the sensor never sees clean rich and lean swings. Fuel trim codes such as P0174 or P0175 stored at the same time point here. Fixing the mixture problem often clears P0153 without a new sensor. 5. **Wiring, connector or heater fault** (rare). A corroded connector, a chafed wire touching the exhaust or a weak heater circuit can leave the sensor cooler or its signal noisy, which slows its response. Heater faults usually set their own code, P0155, alongside P0153. Bank 2 harnesses on transverse V6s run close to the hot rear manifold, so check for melted insulation there. ## How do you diagnose P0153? 1. Read all stored codes and freeze-frame data; fix fuel trim, misfire or heater codes first. 2. Watch both upstream sensors on a scan tool at about 2,500 rpm and compare how fast each one switches. 3. Listen and feel for exhaust leaks at the bank 2 manifold and front pipe on a cold engine. 4. Check the bank 2 sensor wiring and connector for heat damage, oil or corrosion. 5. If the signal stays slow with no leak or mixture problem, replace the sensor and recheck. ## How do you fix P0153, and what does it cost? | Fix | Typical cost | What it involves | | --- | --- | --- | | Replace bank 2 upstream oxygen sensor | $150-$450 | Sensors at the rear of a transverse V6 need more labor and sometimes intake removal. | | Repair exhaust manifold leak | $200-$900 | A gasket is at the low end; broken studs or a cracked manifold cost more. | | Repair sensor wiring or connector | $100-$250 | Splicing heat-damaged wires and securing the harness away from the exhaust. | Full price breakdowns: [oxygen sensor replacement cost](/cost/oxygen-sensor-replacement), [exhaust manifold gasket replacement cost](/cost/exhaust-manifold-gasket-replacement). ## Is it safe to drive with P0153? > **Safe to drive.** Yes, it is usually safe to drive. The engine runs on slightly less precise fueling for one bank, so fix it within a few weeks to protect fuel economy and the catalytic converter. ## Will P0153 fail an emissions test? P0153 turns on the check engine light, so the car fails an OBD-based emissions test in most states. A slow upstream sensor can also keep the oxygen sensor and catalyst monitors from finishing. After a repair, clearing the code resets those monitors, so plan several days of normal driving before a retest. ## After the repair: clearing P0153 Clear the code and drive normally, including at least 10 to 15 minutes of steady cruising on a fully warm engine, which is when the response test usually runs. On a scan tool, the bank 2 upstream sensor should now switch about as fast as bank 1. The fix worked when the oxygen sensor monitor reads complete with no pending code. ## How to prevent P0153 - Fix oil burning and coolant loss early, since both coat oxygen sensors and slow them down. - Use only sensor-safe gasket sealers on the engine and exhaust. - Repair exhaust manifold leaks as soon as you hear a cold-start ticking sound. - Treat lean or rich codes on bank 2 promptly so the sensor is not blamed for a mixture problem. - Consider replacing aging upstream sensors as a pair on high-mileage V6 and V8 engines. ## Codes often seen with P0153 - [P0133](/codes/p0133): O2 Sensor Circuit Slow Response (Bank 1 Sensor 1) - [P0174](/codes/p0174): System Too Lean (Bank 2) - [P0175](/codes/p0175): System Too Rich (Bank 2) - [P0430](/codes/p0430): Catalyst System Efficiency Below Threshold (Bank 2) - [P0171](/codes/p0171): System Too Lean (Bank 1) ## Frequently asked questions ### Can I drive with a P0153 code? Yes, you can usually keep driving with P0153 while you arrange a repair. The engine still runs, but fueling on bank 2 is less precise, which can slowly hurt fuel economy and raise emissions. Get it fixed within a few weeks, and sooner if the engine runs rough or the light flashes. ### Where is the bank 2 sensor 1 oxygen sensor? It is the oxygen sensor ahead of the catalytic converter on the side of the engine without cylinder 1. On many transverse V6s it sits on the rear manifold near the firewall. On trucks and rear-drive cars it is usually on the driver or passenger side manifold, depending on the maker. ### How much does it cost to fix P0153? Most P0153 repairs cost $150 to $550 at an independent shop. Replacing the bank 2 upstream sensor runs about $150 to $450, depending on how hard it is to reach. An exhaust manifold leak costs $200 to $900, and simple wiring repairs usually fall between $100 and $250. ### What is the difference between P0133 and P0153? They describe the same slow-response fault on different sides of the engine. P0133 is the upstream sensor on bank 1, the side with cylinder 1, and P0153 is the upstream sensor on bank 2. If both appear together, look for a shared cause such as an air leak, fuel problem or oil burning. ### Can I replace the bank 2 upstream O2 sensor myself? Often yes, if the sensor is easy to reach from above or below. You need an oxygen sensor socket, penetrating oil and a matching replacement part. Sensors on the rear bank of some transverse V6s are hard to reach and may need intake parts removed, which makes it a reasonable shop job. ### Will P0153 cause bad gas mileage? It can, though usually only a little at first. A slow sensor makes the engine computer correct fuel for bank 2 late, so that bank spends more time slightly rich or lean. Over months, the loss adds up, and running rich for long periods can also shorten catalytic converter life. ### Can an exhaust leak cause P0153? Yes, a leak ahead of the bank 2 sensor is a common cause. Outside air pulled into the exhaust dilutes the readings, so the sensor looks lazy even when it works. Ticking from the manifold area on a cold start is a typical clue. Fix the leak before replacing the sensor. ### Will P0153 pass an emissions test? No, a car with P0153 and the check engine light on fails an OBD-based emissions test in most states. Clearing the code without a fix will not help, because the readiness monitors reset and the fault returns once the test runs again. Repair the cause and let the monitors finish first. ### Should I buy an OEM or aftermarket oxygen sensor? Either can work if it is the correct part for your exact engine and sensor position. Original-equipment or the same brand the factory used is the safest choice for upstream sensors, which control fueling. Very cheap universal sensors that need splicing are more likely to respond slowly or fail early. ### Will P0153 go away by itself? It may go off for a while if the sensor passes its test on later drives, but a worn sensor usually sets the code again. The computer keeps the code in history after the light goes off. If it returns more than once, the sensor or an exhaust leak needs attention. ## Sources - [SAE J2012: Diagnostic Trouble Code Definitions](https://www.sae.org/standards/content/j2012_201812/) - [EPA: On-Board Diagnostics (OBD)](https://www.epa.gov/state-and-local-transportation/vehicle-emissions-board-diagnostics-obd) ## Other oxygen sensors codes - [P0138 O2 Sensor Circuit High Voltage (Bank 1 Sensor 2)](https://diagxcar.com/codes/p0138) - [P0139 O2 Sensor Circuit Slow Response (Bank 1 Sensor 2)](https://diagxcar.com/codes/p0139) - [P0140 O2 Sensor Circuit No Activity Detected (Bank 1 Sensor 2)](https://diagxcar.com/codes/p0140) - [P0141 O2 Sensor Heater Circuit (Bank 1 Sensor 2)](https://diagxcar.com/codes/p0141) - [P0151 O2 Sensor Circuit Low Voltage (Bank 2 Sensor 1)](https://diagxcar.com/codes/p0151) - [P0155 O2 Sensor Heater Circuit (Bank 2 Sensor 1)](https://diagxcar.com/codes/p0155) - [P0156 O2 Sensor Circuit (Bank 2 Sensor 2)](https://diagxcar.com/codes/p0156) - [P0157 O2 Sensor Circuit Low Voltage (Bank 2 Sensor 2)](https://diagxcar.com/codes/p0157) - [P0158 O2 Sensor Circuit High Voltage (Bank 2 Sensor 2)](https://diagxcar.com/codes/p0158) - [P0161 O2 Sensor Heater Circuit (Bank 2 Sensor 2)](https://diagxcar.com/codes/p0161) ## Symptoms - [Why is my car getting bad gas mileage?](https://diagxcar.com/symptoms/poor-gas-mileage) - [Why is my car idling rough?](https://diagxcar.com/symptoms/rough-idle) ## Repair costs - [Oxygen sensor replacement cost](https://diagxcar.com/cost/oxygen-sensor-replacement): $150-$450 - [Exhaust manifold gasket replacement cost](https://diagxcar.com/cost/exhaust-manifold-gasket-replacement): $300-$1,300 --- Source page: https://diagxcar.com/codes/p0153 Updated: 2026-11-03 General information, not a substitute for a qualified mechanic.