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Gaining Horsepower By Pulling the Fuses In A Late Model Camaro

If you are new to owning a 2010 or 2011 Camaro equipped with the L99 or LS3 V8 engine, then you may not be aware of a simple trick that could unleash a few extra horsepower.

There are two specific spark timing tables housed in the memory of the vehicle’s Electronic Control Module (ECM). One is used for cars running high octane fuel and the other for when the vehicle is using low octane fuels. Whenever you drive the vehicle, the ECM is constantly making decisions based on the data it receives from all of the sensors in the engine and exhaust. Over time, the ECM will set your Long Term Fuel Trim (LTFT) to the low octane tables.

The problem: It seems that if someone puts a low octane fuel into the tank, the vehicle can’t recover from the low octane table. Once in the low octane table the car will continue to use that information even if you are now using a higher octane fuel. Of course the side effect of this is sluggish performance, and we don’t really need to explain the benefits of running a higher octane fuel in a performance application. If you just purchased your Camaro you wouldn’t be incorrect in thinking that it isn’t uncommon that at some point the car was filled with a less potent gasoline, especially if it came from a used car dealership or from an owner who was uninformed of this problem and wanted to save a few bucks at the pump. The LTFT’s are, unfortunately, a part of the car’s non-volatile memory. That means the information is stored there, and doesn’t reset when the vehicle is turned off.

However, there is a way around this problem. Although the spark tables are part of the non-volatile memory and cannot be removed, they can be reset. A simple solution is to remove a couple of fuses from the fuse block in the engine compartment. Pulling the fuses will allow your Camaro’s ECM to reset itself to the high octane table. If you are running high octane fuel then it remain in the high table until the ECM again detects a low octane fuel.

The process is quite simple;

First, make sure the car is empty of the low octane fuel. Run the tank down low and refuel with high octane. You might consider running a tank or two through before attempting the fuse pull. Once you have better gasoline in the system, locate the two fuses shown in the diagram below. They are in the fuse box located on the passenger side of the vehicle’s engine bay. The fuses are in position #5 and #20. Remove each of these 15 amp fuses and allow the car to sit for a period of at least a few hours. There is a small, grey fuse pulling tool located on the fuse panel (In the diagram below it would be in the lower right corner area). That should make the pulling of the fuses easier. If possible, remove the fuses and allow the car to sit overnight. Once they have been out for several hours, replace the fuses. When started, the car will attempt to use the high octane fuel trims first, and if you keep high octane fuel in the car it should remain on the higher table permanently. Of course, lowered octane fuel in the tank means repeating the process.

 

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Old info, but it still WORKS. He's right, guys.
 

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:rolleyes::rolleyes::rolleyes:
still makes me :angry:
:confused:what kind of specialists are doing the programming at chevy...
;)the car should be able to adapt itself in both ways (switch the setting if using lower quality gas, and reswitch if premium is in use again)

:lol::lol::lol:
i can remember one branch of gm once (must be a long time ago:lol::lol:) considered
standard of the world:thumbsup::thumbsup::thumbsup:
 

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Thanks for the info, I have always used the best premium fuel (usually Shell V Power premium) but wondered about this data table before. I guess I missed this one before but will try it tomorrow morning....many thanks!
 

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I've also used Shell V Power since owning the car. When I bought it "new" it had just over 600 miles on it. There's no telling what the dealer put into it but I bet it wasn't premium gasoline.

Questions to Apex Chase: Just how much horse power will be regained by resetting the LTFT? Are there any other benefits to resetting them in terms of engine performance and longevity?
 

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Discussion Starter #7
I've also used Shell V Power since owning the car. When I bought it "new" it had just over 600 miles on it. There's no telling what the dealer put into it but I bet it wasn't premium gasoline.

Questions to Apex Chase: Just how much horse power will be regained by resetting the LTFT? Are there any other benefits to resetting them in terms of engine performance and longevity?
I don't know of anyone that has done a before and after dyno pull but it is a significant improvement you can feel. It is all about efficiency and getting the most out of your car. The primary benefit is that your car is going to run stronger.
 

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I pulled the two fuses, 5 and 20, last night and then reinstalled them this morning.

Yes! There is a significant difference in the way the car drives. The idle has smoothed out as has the engine at all RPMs. I didn't have a chance to open her up but if that's the only difference, I'm happy with that. If there are a few more ponies under the hood too, so much the better.

Thanks for the tip!
 

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I pulled the fuses yesterday and left them out for 3 hours. I got in the car to go to work and had to learn to drive it all over again! It made that much difference. It cleared up several issue that I had planned to take to the dealer to fix, now all is well and can not belive the difference.

A must do for everyone! Thanks!
 

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Just remember when yall do this drive the car like you want it to run afterwards. You are training a child how to walk basically what you are doing.


If you have your powertrain warranty keep in mind by doing this it shows you did this fuze pull. They may ? why you did this.


Most have done it after having 87 octane in there cars therefore doing a fuze pull reset your fuel trims.
 

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Discussion Starter #12
I pulled the two fuses, 5 and 20, last night and then reinstalled them this morning.

Yes! There is a significant difference in the way the car drives. The idle has smoothed out as has the engine at all RPMs. I didn't have a chance to open her up but if that's the only difference, I'm happy with that. If there are a few more ponies under the hood too, so much the better.

Thanks for the tip!
I pulled the fuses yesterday and left them out for 3 hours. I got in the car to go to work and had to learn to drive it all over again! It made that much difference. It cleared up several issue that I had planned to take to the dealer to fix, now all is well and can not belive the difference.

A must do for everyone! Thanks!
Glad to see it was helpful. :thumbsup:
 

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I bought my car with 5k on the clock and pulled the fuses at work and let it sit for 3 hrs. I really didn't notice any change so I can only assume it's always had 93 octane.
 

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Is there an octane rating that defines low and high octane fuels? Around here, 91 octane is about the best that can be bought. I see some people (Strick) uses 93 octane fuel.

So what is low octane and what is considered high octane fuel?
 

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They are rated by a formula that defines the blends in the fuels. from 87 to 89 to 91 to 93 octane. They vary in many areas even different states and can depend on "Re Formulated" fuels for areas not meeting air quality standards.

It can all get very complicated but bottom line is just find the best "Branded" fuel with all of the additives that may or may not be included in the "bargan" brands. They cost a little more but belive me, you get what you pay for.

The higher the octane the less chance of engine knock that tells the ECM to retard the timming and thus lowers performance. "Pinging or engine knock is bad, it can damage your engine but most engine designs today have the means to compensate for low octane.

Hope this helps
 

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**** I get my gas at Hess and it's not listed.
 

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APEX CHASE....do you happen to know of any simple power gains such as this for the v6 engine? i understand what u are saying about the fuel trims between 87 and 93 and the v6 recommends 87 octane so i doubt that trick would work for me. ive also heard that you may lose performance in the v6 if you use 93 octane? anyone else heard this?
 

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JWD621:

Thanks for your reply. The information is helpful. I'll be steering clear of any gasoline rated less than 91 octane as long as higher octane fuels are available.
 

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Your welcome, just remember not all 93 octane fuel are equal. Try to buy "Branded" well known national brands to get all of the additives you will need. You will never have to add anything else from the auto supply if you do stick to the major brands.
 
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