ENGINE POOR MILEAGE

We Just Bought This Truck And Within 10 Minutes Of Driving It I Noticed That The Fuel Gauge Was Going Down. The Truck Runs Great And Has...

2006 Mazda3, 2.3 Engine, Automatic, 35,000 Miles. Trouble Started With A Very Hard Start In Mornings Took To Shop They Spent Over A Month...

My Fuel Mileage Has Suddenly Decreased By 10% And Sometimes There Is A Rough Idle Upon Ititial Start Up That Clears Up As Soon As The Engine...

This Vehicle Seems To Run Fine With No Driveability Problems. However, Mpg Suddenly Has Dropped 2-5 Mpg With Same Drivers, Same Routes...

I Recently Changed My Spark Plugs & Connectors. I Also Changed My O2 Sensor. My Fuel Milage Has Dropped To 12 Mpg. New I Used To Get 20...

98 Chevy Cavalier 130,000 Miles, Automatic, 2.2 Engine (i Believe). The Situation Is That My Mpg Have Dramatically Drop In The Period...

Is There A Computer Chip That Will Increase Mpg. If So, Would It Be Cost Effective

I Have A 1989 Ford F-250 With The 5.0 In It. One Morning When I Started It It Sounded Like It Had A Race Cam In It And Then It Smoothed Out...

I've Been Trying To Fix This Problem For Over A Year. I've Changed The Plugs, Used Expensive Fuel System Cleaner, Kept The Oil...

Would Like To Know The Best Way To Reset The Pcm And Perform A Re-learn Of The Pcm. Hoping This Fixes My Issue.