I lost interest in MacGyver after the first three seasons too many stories were ridiculous even by MacGyver and too many situations where it was inhumanly possibly for Mac to come away unharmed. However, this episode was different. It had a believable story and realistic situations. In fact after watching it again on Sleuth yesterday, I can't recall MacGyver making any inventions at all.
The Treasure of Manco is basically about Inca treasure buried centuries ago.
There seem to be factions after it, a rebel group, and another group run by the military under a guy called Captain Diaz. The rebel group is run by Enrique one of Mac's friends or former friend. It seems that Enrique is suspicion of murdering a man for whereabouts of the Inca gold. The writers did a decent job of making it unclear whether he did it or not for the bulk of the episode.
After that it was interesting to see how Macgyver would deal with all the facts.
This episode featured a couple of great actors in Richard Chaves, Theresa Saldana. They aren't household names of course since none of them got any Blockbuster Hollywood deals, but they are well known to anybody who knows anything about acting.
It was a decent episode with a surprising ending, and a realistic Macgyver story.