Loving my E85 right now

[TollKeeper]

I thought it was more of the fuel content sensor (or whatever its called) that told the ECM what duty cycle to run the injectors at, Not the O2 sensors?

Edit: Flex Fuel Content Sensor is what its called.

 

[Dustin Jackson]

I am at 190,000 and just ran E85 for the first time for a tank or 2 and it worked fine. It's kind of cool seeing the MPG drop instantly

I don't know if the previous owners ran E85 or changed the O2 sensors but I understand the Tahoe uses the O2 sensor to read the ethanol content so it's probably best for me to swap in new O2 sensors if I want to run E85 without knowing the history of my Tahoe.

 

[George B]

I have run lots of E85 summer and winter with only positive results. Startups are the same for me regardless of ambient temp.

 

[gooffeyguy]

I've never had a problem with starting on E85 either. I run it often

 

[Fless]

I thought it was more of the fuel content sensor (or whatever its called) that told the ECM what duty cycle to run the injectors at, Not the O2 sensors?

Edit: Flex Fuel Content Sensor is what its called.

They stopped putting physical sensors in the SUVs after 2006. They can be added, though, to later year models. @iamdub did it.

 

[swathdiver]

If you haven't been running E85 prior to 100k is it best not to run it after unless O2 sensors have been changed?

I guess you could say that would be a good practice. Or, don't switch back and forth. If you are going to run it, run several tankfulls at least. Even if it is off 20% and calculates 60% instead of 80% you are still on the high octane tables. My red 6.2 Sierra did this when we ran it on E85 and it had only 80-82K on the motor and O2 sensors at the time. On regular 93 octane, it calculates fine. They are going to be changed out in January.

 

[iamdub]

If you haven't been running E85 prior to 100k is it best not to run it after unless O2 sensors have been changed?

I think what James meant was, since the GMT900 trucks rely heavily on the O2 sensors to calculate the alcohol content, it'd be best to have fresh (and good quality) sensors in place. 100K is pretty aged for an O2 sensor. You won't gain much of anything if you have 65%+ alcohol (ethanol) but it's only calculating it as ~20-something percent.

 

[iamdub]

I thought it was more of the fuel content sensor (or whatever its called) that told the ECM what duty cycle to run the injectors at, Not the O2 sensors?

Edit: Flex Fuel Content Sensor is what its called.

As @Fless said, they switched to what they call a "virtual sensor" in the later years. Mine would always settle around 22-23%, even after new O2 sensors. I later discovered that my new sensors may not be correct for a Flex Fuel Tahoe. I'd still bet that they're correct, but there's room and reason for a sliver of doubt. They seem to read the air:fuel ratio just fine. Rather than getting another set of sensors and hoping it starts calculating more accurately, I just bought the stuff to convert to a physical sensor to KNOW it'll calculate accurately. It was cheaper to do that than buy new O2 sensors.

 

[petethepug]

Got a list o parts from your conversion? I’d love to rule out my PO430 & PO420 DTC that appear only when running e85.

 

[iamdub]

Got a list o parts from your conversion? I’d love to rule out my PO430 & PO420 DTC that appear only when running e85.

Shenanigans start here:

Growing up doesn't have to suck

i guarantee you some old as **** would order the wrong one and complain his bright yellow GTO with a showroom quality stock engine bay has been tainted by the extra 15/16" slack that it has provided and that he will never buy another edelbrock product for as long as they live Y'ain't wrong!

www.tahoeyukonforum.com

Continue here:

Growing up doesn't have to suck

Location! The freaking acoustics literally muted the bass. The sub was between the second row captain's seats. Originally firing upward but we tried all positions (giggity). The sub was working hard. It was making sound the whole time but the bass frequencies were being absorbed by the...

www.tahoeyukonforum.com

And are justified here:

Growing up doesn't have to suck

Didn't like that back to back 90 for flow anyway, glad it didn't work lol Valid point. I disregarded this factor due to my low power levels. Do like that gto hose tho, I've seen it before and thought it worked good but forgot where it came from Got this one off Amazon. I think it's the...

www.tahoeyukonforum.com

You can pick up switched 12V power off the coil pack harness, ground anywhere, and just run one wire to the PCM. Mine had AFM that was deleted so I repurposed those unused circuits to keep it factory-esque. Oh, and you'll have to have your tune switched from "virtual sensor" to "physical sensor". I have HPT.