My wife bougth this 95 200sx to her friend, the problem is the engine light is on since we bought it! her friend say's its always stays on and she even bring it to the dealer to inspect it but they could'nt find whats the problem ( hard to believe).. anyone knows how i can fix this? im not sure if the co2 censor is the problem. and one more thing, this past summer everytime we use the AC and when we got into a stop light the engine dies, so we bring it to a mechanic and still desame. cant figure it out what is the problem. help is appreciated