P0133 – Meaning, Causes, Symptoms, & Fixes
Code P0133 Definition
O2 Sensor Circuit Slow Response (Bank 1 Sensor 1)
What Does P0133 Mean?
The O2 sensor (Bank 1, Sensor 1) is meant to communicate with the Engine Control Module (ECM) about the air to fuel ratio of the engine, and adjust it accordingly. This is done in order to limit the number of pollutants that your vehicle is emitting, and also control your car’s fuel consumption. Code P0133 is triggered when the voltage output that your O2 sensor is meant to send to your ECM does not change quick enough in relation to the air to fuel ratio when you press on the gas pedal.
What Are The Symptoms Of Code P0133?
- Check Engine Light
- Poor Fuel Economy
- Excessive smoke from the exhaust
- Rough running engine
- Poor idle
- Possible Stalling
*No noticeable adverse conditions in some cases
What Is The Cause Of Code P0133?
- Faulty O2 sensor (most common)
- Faulty/Frayed wiring to the O2 sensor
- Exhaust Leak
- Engine Vacuum Leak
- Dirty Mass Air Flow sensor
How Serious Is Code P0133? – Low
This trouble code will most likely not prevent your vehicle from running, but it is still something that we recommend you get fixed as soon as possible. This code can cause harmful pollutants to be emitted from your vehicle into the air, which is extremely bad for the environment. You also will not be able to pass emissions tests with this code present.
Code P0133 Common Diagnosis Mistakes
The most common diagnosis mistake is not doing a visual inspection of the O2 sensor or the Mass Air Flow sensor before replacing it. Often times, the O2 sensor’s wiring is frayed or the Mass Air Flow sensor is dirty, which can both trigger Code P0133 to occur. Exhaust and Engine Vacuum Leaks can also cause P0133 to be triggered.
Tools Needed to Diagnose:
How To Diagnose And Repair Code P0133?
Difficulty of Diagnosis and Repair (1 out of 5)
- Check to see if there are any other codes along with P0133 and clear your Check Engine Light with FIXD.
- Check the freeze frame data in order to pinpoint the issue.
- Conduct a visual inspection of wiring and connector at the O2 sensor for fraying or disconnection.
- Check the Mass Air Flow sensor to make sure that it is not dirty and possibly putting out false readings which affect the O2 sensor. If it is dirty, clean it, clear your codes using the FIXD device, and re-scan to see if the code is still triggered.
- Check for any exhaust or vacuum leaks. If there are any, fix them, clear your codes using the FIXD device, and re-scan to see if the code is still triggered.
- If the problem persists, consider replacing the bank 1 pre-catalytic converter O2 sensor.
Estimated Cost of Repair
For error code P0133, one or more of the below repairs may be needed to solve the underlying issue. For each possible repair, the estimated cost of repair includes the cost of the relevant parts and the cost of labor required to make the repair.
- Oxygen sensor $200-$300
- Exhaust repair $100-$200 (if welded to repair)
- Vacuum leak $100-$200