The CEL indicating does not necessarily mean the O2 sensor is bad. Additonal codes could be present and I would suggest getting a scan done to check if there are any other trouble codes.
Most parts stores provides free scanning services. Let me know the EXACT trouble code if any found.
The air cleaner cover being loose could be the cause of the problem.
VAF ( volume air flow ) sensor is attached to it and any vibrations can cause erratic readings.
Friday, July 15th, 2011 AT 3:12 PM