Its an 89 305tbi .030 with 5k miles on the engine. have had a lot of electrical issues with it in the past but have fixed them up for the most part. didn't have any problems with it for a few months until today. here is what i got

13. Oxygen sensor signal stays lean during warm engine cruise

23. Low temperature at manifold air temperature sensor OR Throttle position sensor error

33. High voltage (low vacuum) at mass air flow sensor (or MAP sensor)

43. Low voltage at electronic spark timing circuit

54. Low voltage at fuel pump OR Low voltage at Fuel pump relay OR Output failure at quad driver module

I have have the codes 13, 23, and 33 come up in the past. i have replaced the 02sensor and the wire for it. I have replace the air temp sensor and the wires for that as well. and the same for the map sensor. i use to have a huge problem with the knock sensor going off but lately i it hasn't shown up. but code 54 ive never seen the past year and half that ive had the car, and today the car started acting like it was running on a couple of dead cylinders. made a horrible noise and didnt want to get up and go. I love this car, and it was treated like **** before i got it. whoever had it did ntn to take care of the car and almost everything had to or has to be replaced including the entire interior. i have put a lot of time and money into this car and just want to get it right. Thanks in advance for all your help. I want to no what all its going to take to fix all these problems for good.

 

I have also replaced the distributor cap and rotor, and all the spark plugs a few minz ago because it is acting like its either misfiring or running on dead cylinders.
somebody plz tell me something.