[denise]

Hi I am new to the fourm...and I need help! I have a 2004 V6 3.9 mustang. I bought it new and the only thing I have added is a stereo. I have less than 48,000 miles on it. About 3 weeks ago I noticed my gas mileage was really bad. Usually I get 19-22 mpg. It has only gotten about 10 mpg last two fill ups so we changed the air filter( it wasnt dirty) to a K&N..but that didnt help. Its not showing any codes, starts fine ,runs fine and yeah even though its a 6 cylinder I have to get into the gas every now and then but not that much! Any ideas? (My other fords..I expect bad mpgs 1982 Bronco V8 & 1990 F150)

 

[watson 1025]

Fuel filter would b the next thing id try. Mine was $7 so its cheap an if its not it it doesn't hurt ur car or wallet.

 

[alrefire]

I avg 14.6 in my v6
Idling for 20 mins in traffic<<<<<<<<<<

 

[denise]

Thank you

 

[mymustang]

A dirty MAF sensor,,can cause that,,or the BARO reading could be stuck,,it built in with the MAF sensor,,try cleaning the sensor and disconnecting the neg side of the battery and let it set 10 mins and reconnect..Has anything else changed,,does it run the same,,is the temp gauge in the same place,,a engine running cold can cause to burn more gas,,Im not sure on that year where its located,,but the intake air temp might be stuck at one temp,or unplugged,,it should be on the air filter box somewhere