Well my sister owns a 98 Civic LX, with an Automatic transmission, has about 117k on it and I don't think she ever changed the fluid in it and its slipping into 2nd and 3rd gears. She wanted me to change the fluid to see if that helped, and it didn't. The check engine light is on and I pulled the codes with my scanner and came up with 3 codes (one was a O2 Sensor Code which isn't a problem) but the other two were the following...

P0700: Transmission Control System Malfunction

P0730: Incorrect Gear Ratio

Anyone have any advice?? I'm thinking that the transmission is toast, but could these codes have any thing to do with it slipping??

 

Can anyone help??