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Thread: Just wondering
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post #15 of (permalink) Old 11-03-2017, 03:19 PM
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Re: Just wondering

Originally Posted by garrettg View Post
The CAI is causing the issue, go back to stock hardware setup or make sure the CAI is sealed properly and have the car tuned by a professional. When its tuned they can also lean out the pe some as well. Run E10 or E0 but its not going to fix a vehicles rich condition in general. The way a car adapts during closed loop ltft processing will never be corrected by fuel type change if the maf transfer model is off due to hardware changes. In a full tilt situation E0 is preferred to E10 as it has more potential energy.
Not a good response, the OP has GM warranty and a tune is out of the question for him, that is is choosing
That is like putting a band-aid on a problem and hoping that will cure the problem

You really need to go learn about Ethanol, it is far proven it reduces fuel mileage, induces lean fuel trims so much so the feds had to put out notice out to NOT use Ethanol in most other gas engines.
Have no idea why since you do not know that history or the OPs Z06, nor looked at his OBS-II scanner recordings, nor understanding the ill effects of running 17-20 % rich what the effects are to internal of some engine parts, to O2 sensors or even the fact running that rich is degrading the life of the CATS,

No valid to want to run a non Ethanol fuel that runs richer when the fuel trims are at the trigger point for rich DTCs. OP needs to get engine BACK to leaner fuel trims
BEFORE going back to non Ethanol gas and his scanner will tell him when trims are back to normal

No do I have a clue why your on engine functions like WOT when the engine would not run correctly on a COLD start only

OP is doing the right thing, correcting things found by his tuner, cleaning out the carbon from running so rich for some time,
as changes he makes using the scanner to see if the fuel trims become normal and using some E10 gas to then see what the fuel trims are like
For a car that is not raced, it barely would see issues related to fuel trims but to determine rich fuel trims he is going the right path in
doing changes, even the gas to get fuel trims correct

Your method or mindset is not correct path for a stock Z06 that GM tuned richer solely because of E10 running leaner

People are up in arms over recent EPA waivers that allow but do not require up to 15 percent ethanol to be blended into gasoline as E10 is already too lean for pre 2008 vehicles .
The 15 percent blend, called E15, would be available only from blender pumps clearly labeled “Passenger vehicles only.
Use in other vehicles, engines and equipment may violate Federal law.”

Here is the EPA’s list of vehicles that should not be fueled with E15:


Vehicles with heavy-duty engines, such as school buses and delivery trucks

Off-road vehicles, such as boats and snowmobiles

Engines in off-road equipment, such as lawnmowers and chainsaws

Model-year 2000 and older cars, light-duty trucks and medium-duty passenger vehicles (later changed to model-year 2007 and older)

**** Because ethanol contains one-third less energy per gallon than gasoline, adding ethanol to gasoline leans out the fuel-air mixture, possibly enough to cause damage.
Several manufacturers have said they will not honor warranties if fuels containing more than 10 percent ethanol are used.
That includes GM.
Pre 2008 vehicles including Corvettes were not designed even for E10, GM had so many customer problems that cars like the C6 had to be slanted richer,
C5s the PCM used a algorithm of what fuel trims and O2 outputs to determine gas quality

In the end the OP has been doing as his tuner proposed and that found the airbridge leak, the dirty aircleaner, the coked up valves, piston tops and lazy O2 sensors
and final test of using some E10 gas will pinpoint if start problems are gone, what the fuel trims are now and then can go back to fuel he wants that work on a
stock engine under GM warranty.

A tune setup for using non Ethanol gas would have the most performance benefit but only when owner wants to go that route, and lastly learn about elevation, density and the grades of gas sold in higher elevation

Mike M - 2001 / 2008 Z06s
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