Fuse Pull: Low Octane Fuel Fix For L99 and LS3. Reset Fuel Map for High Octane Fuel.

[ApexedSS]

0-60 times sounds best
i bought the car used with 4,000 miles so who knows if the car has had less than premium fuel in.

Drag Strip here I come!!!

[He11bent]

I am a diehard Shell 93 Oct kind of guy but I KNOW my car has had 87 Octane in it. After I got the car I even did some testing with mid and low grade to see if it would knock and at what octane, differences in MPG, etc. I was not aware of this issue. I have my fuses pulled since last night and will see how she runs on the way to work in a few hours. It has been a very strong motor so far but doesnt lay down rubber...maybe a chirp once in a while but that is about it.

One thing I have not seen mentioned on why the cars can act like this if you have never put lower grades in it. I think you have too much faith in your fellow man. Its dishonest, but some gas stations put lower grades in the premuim storage tanks. This yeilds a much higher profit per gallon to the owner and some people are scumbags. I had a Mazda RX8 for the last 6 years and it was a fun little car but it HAD to have premium or it would tell you within 20 miles if you put anything but premium in it. This happened only a few times in the 6 years i had the car.

[f5journal]

Hbent...part of the issue is false knock caused by a rattle or such non-combustion related thing. That will also kick the ECU into the low octane table

[imsplitbit]

Ok so I wanted to put my 2 cents in here. I was skeptical that this *fix* would do anything for my car. Which is a 2010 2SS btw. I pulled the fuses 4 days ago even though I hadn't noticed that the car had low power I just wanted to see what it would do. I had serious doubts that it would do anything. Before the pull a trip to work and back took 1/4 of a tank of gas. It was almost perfect. I'd start the trip at one notch and when I got home it was on the next lower notch. After the pull, for 4 days now, the gas it takes to get to and from work is approximately 2/3rd what it was. So now if you divided each 1/4 tank into thirds I only use 2/3rd of the 1/4 tank to get to work and back. I am floored with the results. I get on the car daily. Today I got new tires and decided to take it up to <insert really fast speed I won't admit to here> to make sure the wheels were perfectly balanced. So I'm not driving it differently at all. I'd recommend the pull for anyone who feels like their mileage is off because it made a huge difference for me. I just bought the car about a month ago but I know for sure the car was run with unleaded because the sales guy filled it up for me and he said they don't have premium gas at the dealership. I ran it near dry and put premium and have done so since. Anyway there is definitely a difference for me and it's one that I notice in my wallet which is a good thing.

[edgehead2000]

Imsplitbit, I agree with you. When I got my used LS3 SS, it ran strong because the Chevy dealership flashed the car back to oem, but then I did the fuse pull and now it uses less gas and provides slightly less power. Ironic that the pull which is suppose to help us may not be boosting performance on LS3's.

But I do wish we could figure out the correct solution while keeping the stock tune for days we want to burn rubber.

[PQ]

Awesome.

[Gunfighter13]

Did the fuse pull last night (L99). Worked great. I did not disconnect the battery, just pulled the fuses.

[90503]

My fuse pull story: Did first one...did not notice a change...figured I was good from the get-go....Did another one recently, several months after the first one, and noticed considerable improvement.

Why no better on the first one?...Only difference I could think of, was that I did the first one after the car had been sitting unstarted for several days. The second one I pulled the fuses right after I had finished driving it around for a while beforehand.
I mention this because I thought I read posted somewhere on the forums, that the ECM or whatever it is, "powers down"?? over time after the key is turned off....my "guess" or theory...lol...being that on the first one, having sat for a while, did not "recognize" ?? the fuse pull, but did on the second try.

Just saying might or might not be anything to it, but my second one "took" for sure, and I did not disconnect the battery on either one.

[hapisok]

out of curiosity...would pulling the 2 fuses and just rolling the ignition switch over reset the ECU tables without having to disconnect the battery?

by applying the circuit with voltages, its possible that those tables being "latched" in volatile memory can be reset due to the presence of ground. pull fuses, roll ignition over (not to start but to ON), turn off, reinsert fuses and restart.

maybe this has been tried already but this is currently on page 77...

[jaysonstuart]

Has this issue been corrected in the 2012 models? Mines still new but I'm curious if I happen to run into the issue later.

[90503]

Originally Posted by E.T.

I hope someone finally figures this out. It's ludicrous that you have to keep doing fuse pulls and battery disconnects to make your car run strong.

If you really catch the mod bug, keep in mind, a tuner will be able to "fix" your car for good. Why GM couldn't do this to begin with is beyond me.

I agree, it's a very unfortunate issue that's always in the back of your mind that we shouldn't have to deal with.

With all the aftermarket "fixes" out there...skip-shift eliminator, and what-not I would hope there would be a "fix" for this of some kind, instead of it still being a big mystery at this late date.

[E.T.]

Originally Posted by 90503

I agree, it's a very unfortunate issue that's always in the back of your mind that we shouldn't have to deal with.

With all the aftermarket "fixes" out there...skip-shift eliminator, and what-not I would hope there would be a "fix" for this of some kind, instead of it still being a big mystery at this late date.

This is one reason I'm really glad I decided to get a tune. I'm a little OCD about this car, and I know I'd always be wondering if I was running the right octane table.

[PQ]

Originally Posted by jaysonstuart

Has this issue been corrected in the 2012 models? Mines still new but I'm curious if I happen to run into the issue later.

We can find no comfirmation of this. It's assumed that it should work the same but we just dont' know.

[90503]

Originally Posted by E.T.

This is one reason I'm really glad I decided to get a tune. I'm a little OCD about this car, and I know I'd always be wondering if I was running the right octane table.

Not familiar myself with all the tune business...I just know I will never put in low octane fuel...can't understand why there isn't a simpler way to by-pass this, or have it recognize higher octane on its own, especially after this same thing has been going on for a few model years now ...dunno...