So you replaced both the sensor and pigtail, driving it for a month without issue and now all of a sudden the code is back or been driving it for a month with the CEL on? Either way, you have to chase the issue back through the wiring if you replaced the sensor and pigtail(blue Toyota sensor is what you bought?) and then possibly through the ECU. There's another post a few threads down and looks like he's chasing the same issue. With no luck either. It's a stubborn code, the components that control it are old and can do wonky things. Mine popped on at a stop light with the truck not even moving. If I were you, I would be rewiring the main harness to the ECU shielded cable at this point.
And I know it's tempting to do things to the distributor to get the power back, but you're not helping matters throwing the timing way off the chart.