Q: Bad egr causing lean in o2 sensor

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I hooked up my obdII reader and was getting codes 0401 and 0153, first relating to the egr and the second relating to a o2 sensor reading lean. I inspected my vacuum lines and found a decayed line leading from the egr pick up tube to the egr sensor. i replaced both line from the pick up tube to the egr sensor and performed a vacuum test by applying a vacuum to the egr valve. the truck stalled out. So my question is this. Could the leak in the pick up line from the egr tube to the egr sensor caused a big enough issue to throw a lean code with the o2 sensor. I reset all the codes and turned the CEL off. Going to drive it and see if the codes come back.

My car has 157000 miles.
My car has an automatic transmission.

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). Oxygen sensors in your application should be replaced every 100,000 miles as degradation in the responsiveness of the sensor will typically not appear as a trouble code. If the codes recur, and you need assistance, please request a check engine light diagnostic. If you have further questions or concerns, do not hesitate to re-contact YourMechanic as we are always here to help you.

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