Can a bad EGR valve cause o2 sensor code?
Any vacuum leak, including the leak in the EGR valve control system that you described, could cause the P0153 code. If the two codes do not recur, you should still check the output of the oxygen sensor for correct waveform and output (switching between 0.2 to 0.9 volts).
What is the code for a bad EGR?
EGR valves can malfunction by becoming stuck open or closed due to carbon buildup. When the trouble code P0401 is set, CO2 is reintroduced to the combustion chamber at the incorrect time or in incorrect amounts, which does not decrease the combustion temperature sufficiently enough to prevent the increase of NOx.
What does the EGR error code p0401 mean?
In the shop’s defense, replacing your EGR valve probably would eliminate the error code, turn off the CEL, and allow you to pass emissions inspection. One thing is certain: the P0401 error code specifically means you have “reduced flow” in your exhaust gas recirculation system.
What does it mean when EGR valve is still working?
Safety first! Once you remove the EGR valve itself, shake it. If you hear the valve inside opening and closing, this means that it’s still working and that you can probably get away with cleaning to get things back in order. If you don’t hear this opening and closing sound, there is less of a chance that it will recover.
Do you need to change your EGR code?
Sure, the technician scanned the error code, but just because it means your EGR is failing, doesn’t mean it needs to be replaced. Unfortunately, sometimes shop owners force their technicians to take the simplest, most obvious route rather than spending extra hours diagnosing a problem more thoroughly.
What causes a p0401 code on a PCM?
Here are the common causes of P0401: 1 Clogged EGR passages 2 Faulty EGR valve 3 A failed sensor (e.g., differential pressure sensor, manifold absolute pressure sensor, etc.) 4 Inadequate vacuum supply to the EGR valve 5 Circuit problems, such as damaged wiring and loose connections 6 Issues with the PCM, such as software in need of an update