Hey i got a 2000 mazda mvp today my wife called me and said the check engine light was on so when i got home i pulled the codes and got codes P0171 & P0174 so i looked up the codes and it says

P0171: System too Lean (Bank1)
P0174: System too Lean (Bank2)

we took a 120 mile ride yesterday and she said she added oil this morning and it was slightly over filled soo what am i looking at here ??

 

Oxygen sensors are reading to lean. Probably time for a tune up and time to replace the O2 sensors.

 

Lots of things to look at!

This should help quite a bit!

http://autorepair.about.com/cs/faqs/l/bl175h.htm

 

Check for vacuum leaks.

 

oojbearoo, is there any black smoke coming out of the exhaust pipes?

 

Had the same codes on my truck. After i replaced the O2 sensors i no longer get the codes.

 

oojbearoo, keep us posted of your results.