P1147 and P0138

[wisehunter1]

Hey,
I've been getting these codes with the service engine soon light on for a couple of months but I've always just cleared them since they're O2 sensors. They'll usually reappear every time I make my monthly 130 mile trip. I was wondering if I'll be fine not replacing the sensors. Like are there any long term problems that can arise?

Thanks!

[ARKQX33V6]

Mileage?
These sensors have a life span, they get retarded with age and use, how is your MPG, worse or better than usual?

[wisehunter1]

just hit 130,000 miles. I usually go about 160 miles on half a tank. So I guess that would be about 16mpg? which is kinda bad