Chevrolet Repair: 2000 chev malibu v6 idle problem, chev malibu, vacuum leak

Question
Hi I have a 2000 Malibu 3100 v6. The idle on the car fluctuates up and down when in park. no check engine light on. I did scan it with my snap on scanner and got code p1133 (o2 sensor)...not sure if its the one before or after the cat. When e-tested this month it just passed right on the limit on the HC ppm reading. Also changed the front pads today,the car was running when I was pumping the brake pedal to set the pads and the engine idle really dropped. Would the o2 sensor be the problem?..vacuum leak? Hate to change a sensor if its not the problem its expensive....any ideas where to start? Heard of any similar problems on this engine? Your help would be great.

Thanks Joe.

Answer
Hi Joe, Not sure what to tell you on this one. Try this though, Disconnect the MAF sensor and see if the corrects the problem. If it does then that sensor is bad, you can do this with other sensors too. The PCM will use a default value when the sensor is disconnected.

Hope this helps you

Have  a Nice Day       Mark