MPG Stinks after front dif and transfer case replacement

[Floep]

You sure your expert did not make any programming entries when he did the wonderful changes , trans case diff?

 

[Doubeleive]

when did you add the light bar and push bar? those things alone will knock your mileage down, did you put in anything else in the back? anything heavy?

 

[HiHoeSilver]

Wait... Why was I under the impression that Tech 2's cost thousands of dollars..? Am I missing something?

Www.chinacardiags.com

 

[Rocket Man]

Wait... Why was I under the impression that Tech 2's cost thousands of dollars..? Am I missing something?

They used to but now you can buy a clone. Same thing, built in the same factories as the ones made for GM.

 

[Jolly Roger]

You sure your expert did not make any programming entries when he did the wonderful changes , trans case diff?

I haven't a clue but always suspect it, and thats the problem with this Wizard of Oz behind the curtain BS that too many of us are made to endure or succumb to. Im a hacker at heart, and I truly believe if you want something done right you have to it yourself. Unfortunately doing things yourself/right directly depends on how much spare time your willing to educate yourself on the subject matter at hand, and it seems to be getting more and more complicated each day. The internet is and can be a wonderful tool but the information compiled there is often more fictitious than factual. Taking a keyboard professionals advice these days can be a dangerous venture and their facts and "experience" are all to often regurgitated opinions of others just as mislead as they are. This forum is a wealth of knowledge consisting mostly of people who have "been there done that". It seems to be full of people with TRUE hands on experience, knowledge and guidance. I sincerely thank you all for your valuable time!

when did you add the light bar and push bar? those things alone will knock your mileage down, did you put in anything else in the back? anything heavy?

No Sir, bought the truck with the push bar on it and the light bar was added after I was fully aware of the mph plunge. My mph went from 16 city to 11 right after the diff and T-case were installed.

 

[Jolly Roger]

What are the symptoms of AFM going bad?
My truck only has 68000 miles on it, I thought Id be immune to this problem for at least a bit longer?

 

[Floep]

Get the RANGER plug in gadget, no more AFM, first thing I did and get better mileage without the 4 to 8 headache

 

[Rocket Man]

Get the RANGE plug in gadget, no more AFM, first thing I did and get better mileage without the 4 to 8 headache

Fixed it

 

[swathdiver]

...the O2 sensor wire was wrapped around a drive shaft. They repaired it. I cant see any new codes on my dash because the CIL stays on all the time due to a gas tank purge valve error.

THIS is most likely the problem.

Hey fellas, didn't someone here who lives in Anchorage buy a Tech-2 in the last year or so?

 

[Jolly Roger]

Get the RANGER plug in gadget, no more AFM, first thing I did and get better mileage without the 4 to 8 headache

Fixed it

The Range AFM delete is on my list but I wanted to make sure my shop couldn't just do it for me before I shell out $200.

THIS is most likely the problem.

Hey fellas, didn't someone here who lives in Anchorage buy a Tech-2 in the last year or so?

You think an o2 sensor/wire could cause such a mpg loss? You know, come to think about it my son walked behind my truck last month and said it smelled rich. hmmm


I also put 37 inch tires on it the same day the T-case was changed....I wonder if that could be.....Im kidding.

 

[Rocket Man]

The Range AFM delete is on my list but I wanted to make sure my shop couldn't just do it for me before I shell out $200.



You think an o2 sensor/wire could cause such a mpg loss? You know, come to think about it my son walked behind my truck last month and said it smelled rich. hmmm


I also put 37 inch tires on it the same day the T-case was changed....I wonder if that could be.....Im kidding.

Your ECM uses O2 data to determine fuel ratio. If it’s in doubt it will run rich as a safety measure so you don’t burn a piston from being too lean.

 

[iamdub]

The upstream O2s are near the forward prop shaft? I know the downstream ones are and have recent experience with their wires being wrapped around the shaft, but I can't picture where the upstream ones are in relation. If it's the downstream O2s, this would not affect your fuel mixture.

 

[swathdiver]

You think an o2 sensor/wire could cause such a mpg loss? You know, come to think about it my son walked behind my truck last month and said it smelled rich.

The engine relies on them to know whether or not to adjust the amount of fuel delivered to each bank of cylinders. Without such knowledge, they will pump way more fuel to protect the engine. The other downside is that the catalytic converter on that side may soon become damaged and require replacement. Fix it right ASAP. Use OE or mimic the OE wiring as changes in it may affect the readings, fooling the computer because the resistance is too high because of a solder joint or butt connector when there should not be one there.

 

[swathdiver]

The upstream O2s are near the forward prop shaft? I know the downstream ones are and have recent experience with their wires being wrapped around the shaft, but I can't picture where the upstream ones are in relation. If it's the downstream O2s, this would not affect your fuel mixture.

Left bank upper sensor is right above it. Yeah, someone posted photos recently of the same, can't remember or was it Randy?

 

[Jolly Roger]

I've watched a few videos and broke out the Chiltons,...I cant see how on earth the o2 wires would/could ever get close enough to the drive shafts to "wrap" around them. Maybe Im missing something.

 

[Rocket Man]

I've watched a few videos and broke out the Chiltons,...I cant see how on earth the o2 wires would/could ever get close enough to the drive shafts to "wrap" around them. Maybe Im missing something.

Wait...you’ve watched videos and looked at a Chiltons ( crappy excuse for a service manual btw) but haven’t actually looked at your own vehicle where the shop repaired your O2 sensor wires? Any particular reason you haven’t put it on jack stands and had a good look? Maybe see how close the wires are to the prop shafts? All of this conjecture might be resolved with a good visual inspection. Most mechanics are terrible with wiring.

 

[Fless]

Left bank upper sensor is right above it. Yeah, someone posted photos recently of the same, can't remember or was it Randy?

Might have been the one that @iamdub posted, but that was the transfer case encoder wires on the front propshaft.

 

[Jolly Roger]

Wait...you’ve watched videos and looked at a Chiltons ( crappy excuse for a service manual btw) but haven’t actually looked at your own vehicle where the shop repaired your O2 sensor wires? Any particular reason you haven’t put it on jack stands and had a good look? Maybe see how close the wires are to the prop shafts? All of this conjecture might be resolved with a good visual inspection. Most mechanics are terrible with wiring.

I know, I know,...and it pains me to great extent....Long story short..
I used to be a Jeep guy, had a nice garage and any tool you could imagine. ASE certed, engine swaps, custom roll bar fab, suspension fab, you name it I did it all...Got married had kid with medical problems and so many hospital bills I couldn't count em all. Downsized home = No more garage and fewer tools.

 

[Jolly Roger]

Happy 4th guys!
Thank you all who have served our great country!

Did you know the legal separation of the thirteen colonies from Great Britain in 1776 actually occurred on July 2?

.....Reading rainbow music cue...

 

[Rocket Man]

I know, I know,...and it pains me to great extent....Long story short..
I used to be a Jeep guy, had a nice garage and any tool you could imagine. ASE certed, engine swaps, custom roll bar fab, suspension fab, you name it I did it all...Got married had kid with medical problems and so many hospital bills I couldn't count em all. Downsized home = No more garage and fewer tools.

Oh man sorry to hear. Hope you get it figured out.