[crisspy24]

What does it mean to fully open the valve by pulling the fuse? And does that cause any long term damage to the vehicle?

[Nothing like an SS]

It means the valve is fully wide open at all times, no it won't, it is only bypassing the muffler, the last stage of the system. Neighbors on the other hand, those could be permanently damaged! LOL

[crisspy24]

Does pulling the F51 Fuse cause a check engine light at all?

[Justcruising]

None at all

[GroundhogSS]

Originally Posted by crisspy24

Does pulling the F51 Fuse cause a check engine light at all?

I've had it out for probably 70K miles and no problems yet, and no CELs.

[RIPws6]

It’s a great alternative to buying an upgraded exhaust system. I drove mine without the fuse for a year. Big improvement but once you get to cruising speed, AFM takes over and your car will go from nice growl to silent. So having open valves is good, getting rid of AFM is even better. I don’t want to assume you know what AFM is so in short, Active Fuel Management is what turns off 4 cylinders and puts you in V4 mode. The factory puts this in to avoid charging a gas guzzler tax on the sticker. The latest version of the GTO did not have AFM so as a result, anywhere from $1000-$2000 was added to the sticker.
So, when you pull the fuse, be aware that after you hit cruising speed, it’s going to be quiet, no matter what you do. I eventually got MbRP exhaust, which has no valves at all, and I still have the same issue for the above stated reasons.
To save wear and tear on your lifters, you can either tune out the AFM or purchase a product called the rangefinder for about 300 bucks. This little gadget plugs into your computer port and will harmlessly disable AFM for as long as it is plugged in. Many people here are using it with no issues.

[JamesNoBrakes]

Originally Posted by crisspy24

Does pulling the F51 Fuse cause a check engine light at all?

It does cause a code, you won't see it, but a dealer can when they scan your car.