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Q: p0101 and p0172 codes

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Before this problem there was an evap leak. That resulted in me failing my emissions test. So I took it to a lexus dealer to diagnose and repair the problem. They found a leak in a hose connected to the intake, which they replaced. After getting it back these codes came along and the car idles very rough. This will cause me to fail emissions again. Could it be something the did not do correctly? Something I can fix?

My car has 93000 miles.
My car has an automatic transmission.

A: Hi there: The P0172 error code indicates t...

Hi there:

The P0172 error code indicates that there is too much gasoline being detected in the exhaust gases exiting the combustion chamber. The ECU uses a number of instruments, such as the mass air flow sensor (MAF), oxygen sensors, and manifold absolute pressure (MAP) to monitor the air-fuel ratio of the engine. Any of these components can be faulty which may be the source of the over rich situation causing the emissions failure. The P0101 code suggests that the mass air flow sensor might be the trouble component that is causing this issue.

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