GMC Envoy problems?

Test drove an ‘02 envoy 156k miles, price 2k.

Had an ABS light and codes for a misfire, but didnt feel like it was misfiring when i drove it. Had a cat issue which could possibly contribute to a misfire code? I would just straight pipe it. Engine bay looked clean no leaks, oil cap clean. Shifted smooth, ran well. Frame looked like mostly surface rust didnt see any real rot.

ABS code said wheel speed sensors

There was also a bit of a clunking noise from the back when driving. This was my biggest concern, what are some possibilities that this could be?

For 2k i feel like its not bad, vin check was clean. is there anything here that sounds potentially catastrophic that would make it a bad buy for that price?