I have a 91 lincoln csi and gas gauge reads CO .what does this mean.

Fuel pumps outside the gas tank have nothing to do with fuel gauge readings. There is a fuel level sender unit inside the tank with a float which supplys variable ground circuit to the gauge. If you can find the wire to this unit, you can ground it to see if the gauge now goes to full. If so, sender unit in tank is bad, or has bad wiring/ground.

A "C" code is a chassis code, but I cannot find out exactly what that one means. Take the car to your local auto parts store and have them run a free diagnostic test on your OBD-2 on-board diagnostic computer and tell you exactly what the problem is.

Talking about fuel gauge issues and how do you how do you diagnose, ... is the dash unit right here, and obviously the gauge doesn't read correctly. ... to fix the fuel gauge, so you can actually fix the fuel gauge electronically by reflashing the program. ... How to Troubleshoot a Malibu Fuel Gauge & Dash Light Not Working ...Could be a bad fuse - fuse # 17 is a 15 amp fuse for the fuel gaugeCould be a bad float on the fuel gauge sending unit inside the gas tank ( it's with your electric fuel pump ) If the float gets a pinhole or crack in it , the float fills with gas and sinks so the gas guage reads empty all the time Could be a wiring problem

It means circuit open this usaully happens when u put too much gas in ur lincoln u probly filled it up pass then sensor that reads it @least that's what the lincoln mechanic told me I have the same problem jus continue to drive it and burn the gas

What were the emission readings, e.g.
what gas was to high?

That is how you start to figure out your problem

HC,CO,CO2,NOX ?

Circuit Open is what it means most likely u over filled ur gas tank pass the gas sensor it happened to me I never knew u could have too much gas a lincoln mechanic told me to jus drive and itl burn off excess gas and go back to normal

co means circuit open the fuel sending unit in the tank needs to be replaced

I have a 91 Work at a auto parts store Cant get most parts the 91 is different.Sometime you can go up to a 94 and the parts will match.Other than that do as I had to do Junk yard

If the gas gauge is not showing how much gas you have.The sending unit in your tank is bad replace it.

im having a problem with my oil gauge on my 91 chev cav z24 3.1 liter 2 door. when i use the gas my oil gauge reads properly or atleast i think so. but when i'm idling at a stop my oil gauge drops and reads as if ther was no oil in in the engine anyone have any answer to why this mit be please im at a loss with this one?????