It could be a couple different things but, I always tell people to check your gas cap first. This is an evaporative emission problem and the system is not holding a vacuum due to a gas cap not tight, etc.
You can run a diagnostic test for the knock sensor, on your 2005 Chevy avalanche, by hooking the engine up to a diagnostic tester.
2.2L eco-tec
P0496= evaporative emission system High purge flow
unskew the bolts
In a 2005 Chevy Aveo, the diagnostic port, also known as the OBD-II port, is located under the dashboard on the driver's side. It is typically found near the steering column, just above the pedals. You may need to kneel down to see it clearly, as it is positioned close to the bottom of the dashboard.
Mine was a disconnected cable to the charcoal filter near the gas tank.
where is diagnostic link connector for Honda odyssey 2005
Trouble code P0142 means:O2 sensor circuit malfunction (Bank 1 Sensor 3)
Sounds like its from one side? Ur shocks
i had the same thing happen to me and simply had it hooked up to a diagnostic and reset the codes and it fixed it apparently a sensor had malfuntioned and was not communicating with the computer
when to tune up my 2005 chevy
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