hi i drive a 98 volvo v70 nonturbo with 208k on the dash oem cat discountinued install aftermarket cat keep getting code p0133 02 sensor circuit slow response bank 1 sensor 1 but was getting code before cat was change how to fix

When installing a new cat, always install new O2 sensors with it.

If you had this error code before replacing the cat, you should have replaced the front O2 sensor before replacing the cat.

Easy to replace. Most auto parts stores will loan you a free 7/8 socket to remove the O2 sensor. The plug for the O2 sensor is on top of the transmission, below the ABS pump. There are 2 sensor plugs, check youtube for easy explanation. FCP also has a video for a turbo, same as yours but harder to access.
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Keeping it running is better than buying new

How old is the upstream (before the cat) O2 sensor? If still original, it's due for replacement. That said, it might be that you have a vacuum leak somewhere. Check closely the vacuum lines and PCV components for any leaks/cracks/cuts.

-Will
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XC60 / Odyssey

when i change the cat and mufffler i put 2 new bosch oem sensor on my volvo still getting p0133 was getting it before i change the cat so ill check for vacuum leak on my 98 volvo v70 with 208k