bad gas mileage
yes
Yes it certainly could cause bad gas mileage especially if it is plugged up or if your car's oxygen sensors readings are faulty.
No, a bad fuel pump will cause a no run situation.
It could, yes.
Yes it can reduce gas mileage. There are usually two kinds of faults with FPR that reduce gas mileage. 1. Excessive fuel pressure. 2. Fuel leaking through vacum. Both these faults result in bad gas mileage.
It is one of many possibilities.It is one of many possibilities.
A bad thermostat can cause a decrease in gas mileage. If the thermostat is stuck open, the engine will tend to run cold. Not only will this result in a perpetually low temperature gauge reading and poorly performing heater. It will also cause the ECU to richen the mixture, since the engine will appear to be warming up to the ECU. This will result in poor gas mileage. Replacing the thermostat will allow the engine to fully warm up, which will restore gas mileage as well as heater performance.
Bad gas mileage can sometimes be attributed to a vehicle in need of a tune-up. Have your car serviced and see if that improves the gas mileage.
Clean the MAF sensor with CRC MAF cleaner.
hummers
Putting your foot down too hard on the accelerator.