1998 ford ranger xlt

My check engine light came on a while back then went off and now its been on for a couple months, I had the code checked and it says it's p0153 o2 ckt slow response I am mechanically retarded so could someone explain what this might mean ? I have 50 thousand kilometres on this engine i think another code they gave me was IYO31N

THANKS FOR ANY HELP

That code comes up when your pcm doesn't receive any input from the o2 sensor within 2 minutes after starting. You probably need to replace the o2 sensor--which can be a PITA. Has your gas mileage dropped recently? When mine went bad, I could tell I lost about 2 mpg. Is the other code p1031, maybe? P1031 is HO2S Heater Current Monitor Control Circuit Sensors 1, but I don't know of the exact cause for it. It reads that the voltage across the sensor is off. I would replace it.