Ok

so we're testing the O2 sensor with a snap on scanner, and the device made the engine idle weird even tho it dosen't affect it.....I was in the car reving it at 2 and the devices screen flashed to the engines idle and made same ticking sounds, at 2k it said Lean/rich over and over and my dad says that means the o2 sensor is fine....BUT the engine and device we're acting weird....then I reved it up to 6K and held it going from 6K- 8K ish wasnt really looking then my dad said cut it, when i looked at him the air around us was all blue/foggy looking (we're in a car port at a mobile home) and i looked back when i got out and blue smoke was comming out....

Whats that mean