Contour Enthusiasts Group Archives Forums General Troubleshooting 4 cyl auto engine troubles ?

I have a 96 Contour 186,000 Miles. Trans rebuilt at 177,000. At that time mechanic changed water pump, both belts and thermostat. I also got new tensioners. I have new fuel injectors and oxygen sensor. But I still have performance problems. I get the same fault code, P0171. Cyl 1 Bank 1 too lean. new injectors didn't correct. Help!!