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2009 Sierra 5.3. Horrible Fuel Economy. Help!

Parsonsjb88

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Parsonsjb88 Enthusiast

Parsonsjb88

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With the bb tune it will all depend on what mods you have installedd on the truck. A tune from stock will def show a difference especially without or reduced tm.

 

 

I just have a Volant Cold Air Intake right now. I would like to get a corsa exhaust and a set of headers (still havent decided on long or short or the brand). I am just hoping that the tune will help with the shifting in the transmission, with the larger tires I notice it tends to shift at awkward times and I get the feeling this is also contributing to my lower fuel economy.

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RockySierra Enthusiast

RockySierra

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Get rid of those E-3 plugs NOW. They are just like "snake oil" GM Trucks benefit from the AC/Delco plugs, Ford benefits from the Motorcraft/Autolite plugs, and Chrysler products generally the Champion plugs. Also, the issue with letting your plugs go to 100,000 miles is that every engine runs differently and will wear differently. Some plugs may be fine at 100,000 miles others will be completely worn out and should have been replaced at 60,000-70,000 miles. Many mechanics out there also frown upon doing the 100,000 mile plug change outs due to fear of the plug being "welded" into the block. This happens quite often from what I've been told. Ford's are notorious for it too.

RockySierra Enthusiast

RockySierra

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One lest thing I want to add is to make sure you do a re-learn for the onboard computer. Take the battery cables off, touch them together, leave them off for 30 min or so, then put back in and go drive normally. Allow at least 1-2 fill ups of gas and see if there is any improvement. I've seen it happen for folks on here from years past.

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