how to replace fuel tank sending unit? on 2001 Honda Passport

the check engine light came on and the fuel level hand does not register acurately.the diagnosis was fuel sending unit.also a warning about a co2 sensor? your knowlege of this could help me greatly! thanks.

Asked by for the 2001 Honda Passport
The Emission system in your car needs to monitor the fuel level to run evap tests, O2 sensor failure can pre catalytic converter or post cat converter it can be a heater circuit or performance failure of the sensor. The fuel tank must be removed along with fuel pump assembly to replace the sender unit. Labor time in my guide says 2 to 3 hours labor. There is a company that independent auto repair shops buy their information from that the same information inexpensively to do it yourselfers. The information is year make and model specific repair procedures, service bulletins, component locations, wiring diagrams ect.... Alldata is very easy to navigate
how many sending units are on 2001 honda passport?and how do you determine if they are bad.