does my mpg seem right

[hoe]

no my kon doesnt have that in the computer, or if it does im unaware of it, i do it by math. this last tank was a lil better (11.6) hopefully the current one is even better. guess i may have to look into the o2 sensor. is their 2 in the front or only one? seems to be right around $55 for the sensors i found. would make sense to run a can of seafoam through the gas tank and pc valve before i change the sensor, right?

Mine is a 01 like yours. 00-02 has NONE like ours. 03-06 has the different cluster with the gas economy reader. Which is not accurate IMO. I had a 85 cadillac with that feature, going down hill on any decline its good got 100mpg, uphill or load it got 0mpg according to the pcm. All that monitoring is good, but its not exact. Its actually telling you REAL TIME Mileage. Like in microseconds. Not the average.

Yea, seafoam is good, especially if you have a EGR system on any engine. Im happy my LQ9 does not utilize it. Under my intake manifold was CLEAN. The 5.3 on the other hand is black from carbon entering the egr from the intake. Seafoam will help burn that off the cylinders. But not gain you mileage.

Seafoam would be a waste for your case in my book. The truck has 4 o2s total. 2 of them before your cat converters; and 2 after them. The front 2 are important. Its the ones that effect your mileage by reading your exhaust gas, to tell the computer or pcm your exhaust air fuel ratio. If that is being calculated wrong or slowly, your mileage plumbeths. Change the front 2 02s and be done with it. Then report your findings, and how the truck drives afterwards.

---------- Post added at 05:12 PM ---------- Previous post was at 05:04 PM ----------

I guess I am being useful to this forum. Okay let me break things down that KILLS GAS MILEAGE.

1) Front two 02 sensors
2) Stuck or bad EGR valve
3) Plugged CAT Converter (WHICH THE 02 monitors as well [rear sensors]) <<This is physical, just change the cats


My mileage is always calculated by hand. My vortec max uses premium 93 and runs well. I actually just reset my trip after each gas fillup. I calculate when Im runing low mentally. Its not hard people, dont need a computer for that. Its many times I put 1.7gallon in my truck and got to where Im going while driving very spirited. I change my behaviors if Im city or hwy. People need to drive with anticipation in mind, someone mentioned that above somewhere. Dont hit the gas hard, to slam on it, a few meters ahead of you again.

 

[afpj]

How hard is it to change the front O2 sensors? It's too dark outside when I get home from work, so won't have a chance to look for another week. I assume they're accessible from the engine bay, or crawl under the car? Do they just unscrew like a sparkplug? Since we have 125k miles, I'm expecting some rust or something...can you spray with Wd40 first to soak the threads? Thanks for any info.

 

[yukonjacks]

I get between 11 and 11.5 local driving, but then again I'm traveling on hills, and winding roads. for those of you bragging about 14+ your local driving is like my hiway driving. heck when you guys say your going down the road to a store, its probably 30 miles away on straight flat roads with no stops. For me down the road maybe 3 miles up hill both ways, with 1 stoplight and 2 stop signs. Personally, if your not happy with the gas milage buy a friggen Ford Fiesta.

---------- Post added at 11:23 PM ---------- Previous post was at 11:18 PM ----------

blue have you changed to performance plugs or wires changed the fuel filter etc? after doing all the above and magnaflow and airbox/filter/tube mod i get 18mpg avereage
i do more hwy than in town though

Its hard to accept that your getting 18 mpg in around town in Canada, Dont they use liter and kilometers. You must have one special magical rig to be gettin that much.

 

[JKmotorsports]

When I first bought my truck, it was fully stock and I was getting around 16mpg mixed city/hwy, with the stock 3.73 gears.
If you still have the original o2 sensors, replace them with new ones, but just the front two. If your sensors are old, you should gain some mpg with a fresh set of o2s that can properly monitor and adjust your engine's afr.

 

[jpaeltz]

Yep. pretty consistent, I average about 14 living in Dallas.

 

[afpj]

What brand of O2 sensor would you guys recommend? OEM? autozone special? ebay special? Thanks.

 

[bluekon]

So turns out Guy I bought my truck from was full o shit he told me all the maintanince had been done found the rear diff fluid needed to be changed so I changed that today and I took a peak to find what looka to be OEM sparkplugs still in the truck at 144k miles so I replaced those with some fresh acdelco plugs we will see if mileage goes up

 

[gtbigup01]

You should be getting better than that. I get 13.6 with military base stop and go shot trips driving, with the ocasional walmart run. 12.5 seems too low to me especially for a 5.3

 

[bluekon]

just thought id update after the plugs and diff fluid change my first 1/2 tank i got 13.6 mpg

 

[My01yuk]

That's more like it.