Ok here goes.....
Well i had an ECU malfunction, Grounded all injectors on start-up. No Pulse width, jus straight. Ok Before that happened I had An RPM rev issue(solved) I changed my EGR Valve and I changed the EGR control and It went away, I also changed IACV from a 94 accord. I also have one from a vtec but my car is not vtec so i didnt put it in. My heat sheild is gone, it was never on the car. Do i need one?... Im in Need of A VALVE ADJUSTMENT on cylinder #1 and #2 Exhaust. My car has over 200k miles on it. I have NO CEL. new Fuel filter, and I have Cold air intake. When im on the highway if im going 60 and I let up and now am at 40. i have to stomp on the gas and the intake roars. Feel like am not going anywhere. I filled to half tank and got like 120 miles until i had to fill again. All i do is city driving. Bearly highway. Ihave no idea where to start:
1. Is o2 sensor malfunctioning
2. Is the valves a real problem to MPG
3. Is it low compression to why i cant get up to speed
Now when the ECu grounded all injectors I had no idea so it flooded my engine.
Its not a real big issue but im curious and i need help on this.
Ps. I am a tech student.

 

Scan tool i used in school, Showed ___-----_--_-___----___---__for o2 signal. It lookes like the time and the voltage is not constant.

 

Thats all I get in my 1993 accord EX, actually you are getting a bit better millage then I am. Im sitll working on some things to see if I can improve it and Im sure i need a valve adjustment as well.. Im curious though about your rpm rev problem you fixed by replacing the EGR valve and control unit. What exactly was the problem. I am having a poor acceleration problem until i hit 2200-2500 rpms then it is fine.. is the similar to the problem you were having?

Obviously if you havent done a tune up in awhile, you know, spark plugs, wires, Cap, Rotor, fuel filter it can always help with the mpg's.....

 

Well my next step is a compression test. i havent done one yet, but the valve lash im not sure if it might cuz the problem but they do tick pretty loud. As for the idle problem i replaced IACV, egr and control, and it went away. Kinda weird, as for the acceleration problem its more of a hesitation to accel. idk what it is maybe its just my old tranny, or maybe its the timing i cant say, because it happens at high and low speeds. I spend my whole check at the gas station lol, i wouldnt think anyone would get an better mileage than me.