My 2004 Quad Cab 4X4 with a 4.7 lost a little gas mileage recently, I normally average around 14, but have recently been getting around 12. I still have original plugs, I will change those, is there anything else that I should look at replacing?

I also have noticed some rpm surging when I start the truck, will go from around 6k to around 12k.

Thanks

 

Are you using the air conditioner now? That will cause what you describe

 

Your plugs should have been replaced a long time ago. What about the air filter? Transmission oil? Diff oils? Plug wires? Cleaned the TB? Fuel injection cleaner?

 

Aye, air filter, all your fluids can help. Plug wires/coil packs are worth checking. Clean the TB and there's a chance new injectors would help. Try some cleaner through em first like weed said. Alignments don't hurt either.

 

You have a 4.7 that will wind to 12K?! Yep - plugs, TB clean, filters, tire pressure, Sea Foam.