2000mazda protege 1.6L..showing code P1170what is probable cause?

Question

2000 mazda protege...1.6L engine....trouble code P1170...what is probable cause?

Answer 1

P1170 Front H20S no inversion

When there is no inversion this means there is no switching , a good 02 sensor will cycle from lean to rich this is a fuel control, If this is from the 02 itself then it is considered bias condition whether it is a lean condition or a rich condition. Vacuum leaks needs to be inspected , also do a MAF cleaning, Clear codes if P1170 remains replace front 02 sensor