Nissan Repair: 2000 nissan sentra, vacuum leaks, nissan sentra

Question
my sentra starts but the rpm fluctuates and shuts off i have to restart it adn keep the accelerator down to keep it running after warms up t runs great but hesitates when driving very slow and the rpm fluctuates unless i derpress the accelerator my service engine soon light is on and got the code number PO171 thank you for your help.

Answer
Hi Selvin

Code PO171 means that the car is running lean, bank 1, which is the driver's side.

The first thing I would check is for a vacuum leak. Look for a small rubber hose either broken or disconnected. Sometimes you can hear a hissing sound. That might help you trace it. Other causes of vacuum leaks are broken emission components, such as the MAP sensor, PCV system, EGR, etc.

The fact that it runs OK after it warms up tells me that the fault is in the cold loop, meaning that only components programmed to be active during warm up could be the culprit.

Hope this helps -
aloha
calvin