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Will an Exhaust Leak Throw a Fault Code? (Explained)

Updated: Jan 9

An exhaust leak is a common problem that can occur in vehicles. An exhaust leak can affect the performance of your vehicle and may cause problems with the engine, such as reduced power and fuel efficiency.


One question that often arises is will an exhaust leak throw a fault code or trigger a check engine light. In this article, we will explore this question and see whether a leaking exhaust system could trigger a fault code.

 

Table of Contents:


man scanning a car for fault codes

Will an Exhaust Leak Throw a Fault Code?

Yes, an exhaust leak can throw a fault code, depending on the location and severity of the leak. If the exhaust leak is large enough, it can affect the engine's air/fuel ratio, causing the engine to run lean (too much air and not enough fuel) or rich (too much fuel and not enough air).


This can trigger a fault code, as the engine's computer will detect that the air/fuel ratio is not within the normal range.


In addition to affecting the air/fuel ratio, an exhaust leak can also cause the engine to run poorly, leading to a loss of power and potentially triggering a fault code. However, it's worth noting that an exhaust leak alone may not be enough to throw an engine code.


Other factors, such as the condition of the spark plugs and ignition system, can also contribute to engine performance issues and fault codes.


Can an Exhaust Leak Throw an O2 Sensor Code?

An exhaust leak can potentially throw an oxygen (O2) sensor code, as the leak can affect the accuracy of the O2 sensor's readings. The O2 sensor is responsible for monitoring the air/fuel ratio in the exhaust gases and sending this information to the engine's computer.


If the exhaust leak is causing the engine to run lean or rich, the O2 sensor may detect this and send a fault code to the engine's computer.


However, it's worth noting that an exhaust leak alone may not be enough to trigger an O2 sensor code. Other factors, such as a faulty O2 sensor or a problem with the engine's fuel system, can also cause O2 sensor codes.


Can an Exhaust Leak Cause a Check Engine Light?

An exhaust leak can potentially cause a check engine light to be triggered, as the leak can affect the engine's performance and emissions systems and trigger fault codes.


However, it's worth noting that a check engine light can be triggered by a wide range of issues, not just exhaust leaks. Other common causes of a check engine light include problems with the ignition system, fuel system, and emissions control system.


Will an Exhaust Leak Cause a Lean Code?

An exhaust leak can potentially cause a lean code, as the leak can affect the engine's air/fuel ratio and cause the engine to run lean (too much air and not enough fuel).


This can trigger a fault code, as the engine's computer will detect that the air/fuel ratio is not within the normal range. However, it's worth noting that a lean code can also be caused by other factors, such as a faulty fuel pump or injectors, or a problem with the engine's intake system.


Conclusion

An exhaust leak can potentially throw fault codes and trigger a check engine light, depending on the location and severity of the leak and how it affects the engine's performance.


An exhaust leak can affect the air/fuel ratio and potentially cause an engine code or an O2 sensor code, and it can also cause the engine to run poorly and trigger a fault code.


However, it's worth noting that an exhaust leak may not be the only cause of fault codes or a check engine light, as other issues can also contribute to these problems.


If you suspect that you have an exhaust leak, it's important to fix the exhaust system leak as soon as possible to avoid further damage to your vehicle and to restore proper performance.

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