1991 Integra problems

Hi. I recently bought a used 1991 integra 4-door automatic as a family car. It has few problems that need to be resolved. First is that when you step on the brake pedal the park light turns on. Second when I took the car for a spin the check engine light went on then it won't pass the 3000 rpm anymore. Have any of you experienced this kind of issue?

1. Check your brake fluid. 2. If you pull back the carpet on the passenger side floorboard your ECU will be flashing a code. If you tell us this code we may be able to help. Check it with it on and while the check engine light is displayed. Count the number of times it flashes, there will be a pause, then it will flash it again. If there is a pause then it flashes a differnt number of times write down both codes.

I did manage to check the brake fluid and its still full. What about the brake switch or perhaps the fuse box? Its really hard to troubleshoot when you don't have the wiring diagram of this car.