P0430 Wont Go Away.

[wagonproject]

Had a convertor put on about 10,000 miles ago on my 96 (305). Well the trucks been in and out of the shop for different reasons since then. Well it went in last week with the p0430 code. GM said it was the convertor so I went and had it replaced under warranty at the exhaust shop. Code was cleared and came back on within 50 or so miles. Went back to GM with the p0430 code and another one (forgot the number). But it was about the post 02 sensor which they said the exhaust shop screwed up when they welded on the new convertor by not removing it. Put a new 02 sensor on and went and had the convertor replaced again this time making sure they removed the 02 sensors. Well within 50 miles the p0430 code is back on. Any ideas or suggestions?

[Black02Silverado]

Check out this link. It has some good info on this code.