check engine code with P153 code on 1997 Mazda B4000

v6 4.0L engine with 105,000 miles. MAF was replaced 3 months ago, it runs fine except for marginal gas mileage. thanks for helping

Asked by for the 1997 Mazda B4000
P0153 is bank 2 oxygen sensor issue. Check for air leaks. A diagnostic test needs to be performed to monitor oxygen sensor operation - check bank 2 verses bank 1 - see how they are switching.

It may be that you need a bank 2 upstream oxygen sensor.

This will also hurt your fuel economy...
the light went out today, don't know what to think. thanks for your reply.
Oxygen sensor issues can come and go as drive cycles are continuously being updated, and this kind of code may indeed clear itself in time. Keep a sharp eye - the key to me is that your fuel economy is marginal...which in this truck you're lucky if you hit 15-18 on the is marginal 12-14?