Hello! New to the board, new to 4Runners! I had an '87 SR5 Pickup and still have a '78 Cruiser but that's another matter.

Anyway, I just bought a '94 4Runner from a little used car lot. It's got 170K on it and it ran fine for the hour or so I drove it before I bought it. I get about 40 miles down the road and the check engine light comes on!

So I ran down to the local Checker Auto this morning and had the kid from the counter stick their OBD meter on there. He said it came back with Code 26 "Mixture control continuously rich."

I'm hoping it's a bad O2 sensor or idle sensor. Does anybody know the most likely culprit before I start the "trial and error" method?

Thanks!