Dragon Ball Z Episode 131: More Androids?!
Episode 131 of 291 of Dragon Ball Z, aired March 11, 1992, 25 minutes. Available with English subtitles and dub where released.
Episode summary
Finally becoming a Super Saiyan, Vegeta easily defeats Android 19, but 20 has escaped to come up with a new plan. Vegeta and the others look for the diabolical Android, but it won't be easy.