Alright a week ago i was getting 12.5 mpg. After heeding some suggestions here I replaced the plugs wires, tps sensor, O2 sensor, Ignition Coil, and installed new grounding wires. Currently codes i have 12, 13, 21, 44. Now I did loose one code for broken tps but still have an error for it. Now i will say the stuff i was suggested has improved the fuel economy quite a bit. I'm sitting around 19.8 mpg ish to 19.5. No trouble light comes on while i'm driving though i would like to know if there is more i can do to get rid of these codes in memory not sure if they're even relivent

What engine/tranny have you got??

1986 se 2.8 l v6

Disconnect power for the ECM to clear the old codes.

Near the battery there is a small wire with what looks like an inline fuse.
Disconnect for 15 seconds and re-connect. ECM codes will be cleared.

You now have to drive the car 20-30 minutes for the ECM to relearn.

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