p0133 Oxygen Sensor Circuit Slow Response?

At 247,000 miles, the most common cause is a worn or contaminated upstream sensor. But, it can also be an exhaust leak a bad/dirty MAF sensor. Do not try to clean the 02 sensor if anything checks out, I would get a new one.

what I noticed is that the o2 sensor is slow only at idle very slow sometimes it stays lean for long time. the speed when the code was set was 0 mph ( I saw it on the freeze frame data) when driving on freeway it switches very fast. also, I noticed that the MAF sensor at idle is 1.35g/s. when I do a WOT while driving the o2 sensor read rich but the maximum load that I got is 70%. today I checked the resistance of the heather element of the o2 sensor. it was 9.2ohm. the MAF sensor is clean. about exhaust leak there is an exhaust leak but is after the upstream o2 sensor but not far away from it.it is where the exhaust manifold connects to the cat at the donut gasket. I don't know if it affects the o2 sensor or not

Yes, the exhaust leak can effect the reading at idle. I would fix that first. What happens is the "pulse of the exhaust system can suck oxygen in up into the sensor messing with the readings, at faster RPM speed this will not happen. Let me know what happens after you fix it.