Try starting here
Does your car idle smooth? If you have a large vac leak, it will idle like crap. A small vac leak will cause a slightly rough idle. Small vac leak should not be enough to trip a 1222 code.
Assuming it idles fine, check the fuse to the O2 sensor power circuit to make sure the fuse is not blown. Do a code clear and see if you still get the same error.
Jeff
Bellevue WA
90 535iM - not much stock remains. 3.7 liters, ported head, cammed, 3.73 diffy, M5 brakes, MAFed, yadda yadda yadda
86 Porsche 951 - Track Toy