okay well i have a 2001 chrysler lhs and first i was driving down the road and when i went over 45 mph the rpms were really high so i took it in to the shop and the guy said it was this chip so i went and picked the car back up and well i was driving home the check engine light came on so i let it sit over night and then it went off and then everything was fine. Then driving to work it came on again so i put it back into the shop and the guy found some error and somin was wrong with my speed chip so he replaced it and he took it for a drive and then the guy called me and told me that the speedometer was not working but i needed my car back so he did not have time to work on it. Well driving home i also realized that my fuel gauge on the dashboard goes up and down a little bit and the one on the roof starts at 60 then goesto 90 miles left and then it goes back down and back up. Also my car stalled on me once and my MPG is not working either. So any help would be good because i have spent a ton so far and i dont want to bring it back in if there is somin i can do. and i want to make sure he is doing it right.