I got the check engine light a couple of times…one of the O2 sensors was replaced

I have a 2003 Nissan 2.5 sedan w/69,000. I have maintained it well…religious oil changes, both 30, 000 and 60,000 maintenance. I just had my front and rear brakes done a couple of weeks ago and about a month ago, I had to have the right passenger side floor redone because there was rotting through the floor. Last year, I got the check engine light a couple of times…one of the O2 sensors was replaced…then the other. It was eventually determined there was an issue with the catalytic converter and the engine was also replaced. This was done at the dealership at no cost to me due to my warranty coverage.

For the most part, the car runs well except I have been noticing a slight hesitation upon pressing the gas pedal from being at a stop. I also notice that there seems to be a slight drain of power when I turn on the ac or a couple of times while highway driving. Is this something to worry about?


The loss of power or feeling the A/C compressor is not unusual. The hesitation from a standing stop could be a sign of low fuel pressure and possibley a weak fuel pump. If the check engine light is not on, then I would start by having the fuel pressure tested to make sure it is up where it should be. If it is then there is also a possibility of the mass air flow sensor causing the problem. The best test for the mass air flow is with a scan tool, this way you can watch all of the values as the air flows through the sensor. If one is out of range or close then it will likely be detected.