I'm looking to put a trick turbo stage 3 kit on my 2001 Silverado 1500HD with 6L and 4L80E. I have e85 available around me, so I've been thinking about tuning the truck for it. We take the truck on many long road trips, so I've been looking at adding the flex fuel capability (sensor and OS change) or just pulling out the laptop and flashing in a 93 octane tune if I can't find e85. My question is, other people with early GMT800 Silverado's, will going to the flex fuel OS break any functionality in the truck (ABS, cluster, trans temp gauge, ...)? I looked and ABS modules are different between vehicles that came with the flex fuel OS and mine, so if something major is not going to work, I won't waste my time with the flex fuel OS and just flash the truck if I can't find e85. I'm concerned reading online that the ethanol content in e85 varies a lot depending on season and the sensor plus flex fuel OS would help me with that. If anyone just flashes back and forth between changing fuels, I would be interested to hear your experience on fuel too. Trying to figure out a path forward. Thanks for any help.

 

Never had an issue with cluster gauges etc. get it on ethanol. Don’t look back

 

I have a 2002 silverado and just segment swapped to a tahoe os for flex fuel. I still haven't installed the sensor, so i'm not exactly sure it's going to work, but I don't see why it wouldn't. I used to have a 2001 Pontiac Grand Prix GTP with a supercharged 3800 that I ran on various blends of E85, and had to adjust the tune when the blend changed. it was almost always E70, but I did one time buy a barrel of E98, and so I set up the tune to inject a lot more. it's kind of annoying to have to adjust your tune every time the blend changes, it's also a small amount of work to see what blend you do have. I also have a 2008 Pontiac Grand Prix GXP with the LS4 engine and have converted it to run on flex fuel. it is by far the way to go. being able to run whatever blend of ethanol is great.

 

I've had a 2002 Tahoe flex fuel tune running on pump E85 in my 2001 Silverado 1500HD for the past two months and everything works as expected.