Engine Performance problem
1997 Ford Contour 4 cyl Two Wheel Drive Automatic 115000 miles
Vehicle idle was somewhat rough. In gear with AC on would sometimes stall. On accelleration would hesitate briefly.
Maintenance has been good except never had fuel injectors serviced. Changed out injectors and fuel filter. Now runs somewhat worse. I am thinking a bad fuel pump. Any easy tests for shade tree mechanic for fuel pump. They are expensive. Of note several months ago threw a codePO 171 " lean on bank one". Cleared code and ran good until currently. Had been getting 35mpg.
Does it make sense that it runs worse after changing out injectors and filter?
Thank You kindly