Toyota Repair: Engine trouble codes, vacuum gauge, toyota celica

Question
HI,
I own a 1989 toyota celica. and my check engine soon light is on for 4 different things. i used the jump wire between the two terminals in the diagnostics plug. the codes read as the rpm signal, the EGR, the vacuum sensor, and the air intake temperatur sensor. i was just wondering if it was possible to really have all these things wrong with my car and still be able to drive it. it runs like crap but it still goes. also i was wondering if these codes could be linked to one bigger thing. if not then i was wondering on how to fix these codes so i dont have to pay a million dollars to a mechanic.
Thanks Alot
Josh

Answer
The one code that's really causing the problem is the EGR code #71, for the time being ignore all the other codes.
The 71 code is not that easy to diagnose without the proper equipment, a vacuum gauge is needed and someone that knows how to check the system, it may be more cost effective to just pay the diagnostic fee at the dealer or independent and have them recommend what repairs are needed and just do them yourself.