HOE, how's the 4l80 treatin yah? I know you had some tuning issues with it, but everything work out good?

 

I will do that with the codes in the tune and clear the current codes and see what I get.

 

yah see if that works. Do you think the tranny issues are tuning related or mechanically related? as far as hitting your rev limiter before it shift, you need to lower your WOT shift speed, the MPH shift speed. if you set that too high, the computer references that and TPS, but if the MPH is too high, then it will bounce off the rev limiter because you haven't gotten to that MPH yet. lower those, or even 0 those tables out. Quite a few guys, including me, run the 1-2, 2-3, and 3-4 shift speed to 0, cause the computer doesn't even reference this table unless it's too high, so 0 them out and it should shift just fine.

As far as the other stuff, is the 80 file a stock file? return everything to stock settings and start back from there.

 

pm me a pic or something of your tranny tables, i have HPT so i can't look at your file, but if you could send me a pic of that table that would be great if i could look at that. you said that table is set "high" enough, if they are set to a "higher" mph then it will bounce off the rev limiter before it shifts.

 

P0179 is your problem. Your fuel composition sensor is screwed up on the high side, presumably causing the PCM to think that you're running an 80+% ethanol blend. Since stoich for Ethanol is around 9:1, the PCM is targeting an AFR closer to that than 14.7. That's why you're running rich.

 

Where is this sensor and how easy is it to swap?

If you say its in the gas tank, I'm selling the Tahoe

 

This was exactly my though when I read your first post. I think the sensor is on the drivers side frame rail behind the front tire it will have a fuel line going into it and out of it with a 3 wire plug on it also. Your not going to like how much a new one cost from the dealer.

 

If its what I think it is, it was quoted at $800 the last time I asked about it (for a different reason). Cant I just turn that off in the tune? I'm never going to run e85 in the hoe. Or I'll figure out the impeadence and stick a resistor in the sensor plug to "Simulate"

 

You and me need to change fuel system, I wish my truck was flex fuel and you don't want it, I would think you could probable go though and disable everything in the tune and diagnostics for the flex fuel stuff and set all the ethanol tables in the tune to the same as there gas counter parts. Building a simulater would probable be pretty easy to if you wanted to go that way.

 

Maybe disable the Fuel Composition DTCs, copy/paste B3647 to B3649 and set B3660 to 0 across the board if you won't be running E85.