MPG worse after tuneup

I wonder if one of the coils is not up to par or maybe the plug gaps are wrong. A vacuum leak wouldn't throw a code unless the fuel trims got so far off the computer couldn't keep it in the 25% range. The computer reset could throw off the mileage for a tank or 2 until it relearned your normal driving pattern. Are you calculating mpg off your own records or using the truck computer? My reg cab doesn't have the computer showing it and I've always kept records on all my vehicles.

 

Plug gaps checked before install ...rubber boot changed on coil plus new wire spring replaced on each one
No engine CKA light or codes.

my 2010 doesn’t have fuel computer.........old school way works best......divide miles driven by gallons fueled equals MPG.

 

Not very helpful when it doesnt go lower than 35 eh

 

What do you mean? My stock pressure was 32, and it worked for me.

Edit: I just looked, and it goes down to 26 PSI for OEM pressure.

 

when you choose Lt it doesnt go lower than 35 isa what i ment

 

What vehicle are you driving that comes with LT tires and recommends less than 35 PSI?

 

your not picking up what im putting down so nvm

 

I believe you are confused on how it works. On the top you select the size and load rating of the OEM tires, and manufacturer recommended pressure. Then, you select the size and load rating of your new tires, and it tells you the proper pressure.

So, what vehicle comes factory equipped with LT tires and recommends lower than 35 PSI?

 

right so if your "new" tires are lt it wont go below 35

im not talking about the factory tire side

 

If your new LT tires are actually large enough to require pressure below 35, it will in fact go below 35.

 

oh

 

Ok, so still getting lousy gas mileage after tuneup, inflating tires, MAF and Throttle body cleaning.....
So based on old plugs looking like truck was running rich.......we’re off to clean Fuel Injectors......214k might be time

any good tutorials on cleaning fuel injectors without going to dealer......

thanksin advance

 

Don't go to the dealer or anyone else to "clean" the fuel injectors. Get a bottle of Chevron Techron Fuel System Cleaner and it will do everything that the dealer can do.

Contrary to what some want you to believe the internals of a fuel injector cannot be serviced. The dealers sells snake oil.

 

You don’t like squirting fuel injector cleaner down the fuel line under pressure from can with the modified hose ? Saw a few videos about that

was using Chevron Techron, until I saw results or lack of results.......Gumout fuel system cleaner seems to get better write ups......

it’s the buildup on the nozzles that you’re trying to get clean or else it runs rich

 

Get Tier 1 Gasoline and you will never have that issue.

 

Check out

$25 BG44k BG 44K Fuel System Cleaner Power Enhancer 11oz.

BG44k for injector cleaner.

Did you check the gaps on the plugs before install? That can make mileage drop if not correct.

What mileage were you getting before and after?

 

Yes, checked the gaps, and used Denso OEMs.......mpg prior @19, mpg now 17.5 so 350 miles a tankfull vs almost 400 miles, and that’s what made me notice, is having to refuel sooner on the same drive between Houston and Dallas.

 

Thanks for the advice.....
Yesterday found a shop that used

$25 BG44K BG 44K Fuel System Cleaner Power Enhancer 11oz.

BG44K under pressure for Fuel Injector Flush/Service........what a difference......smoother, quieter on acceleration, gained 10/15 mph on top end on freeway, now let’s see how mpg goes......worth the cost.