I recently replaced both pumps in my '96 300-6 auto and now getting PO171 and 174 codes. I have looked on line at the 8 or so suggested things it could be. I was wondering what people have found that usually caused this problem. I'm sure there probably is one item that happens more then others and I think I will start there.

Thanks for any help.

 

Assuming the pressure is good on both new pumps, I'd start with vacuum lines and cleaning the MAF sensor.