Horn and muffler...


You have joined the best Corvette forum on the planet. 
Did you get the owners manual (OM) when you bought the car? It can provide a lot of useful information in the future.

If you didn't get one, I would recommend getting one at your earliest convenience. They are readily available for very reasonable prices, either used or new.
You have two fuse panels. One is inside on the passenger side "toeboard" behind a removable panel at the front of the floorboard. (There are two latches that secure the panel)
The second, is in the engine compartment near the battery, and this is where your horn fuse is located. Unscrew the ****, lift off the lid and you will see a diagram sticker attached to the underside of the lid. Your horn fuse is #11.
Try to give us a bit more info on your muffler if you could. Is it corroded through? Is the mounting flange broken at the weld (common problem on earlier C5s btw) where it connects to the "mid pipe" section? There are a couple different ways to approach this, depending on what the problem is.
HTH


What did the shop that failed your inspection tell you about the muffler? Did they just say "you need a new muffler" and let it go at that? Still need more info.
On the horns, did your old fuse look OK? Was it blown? A relay (#36 and also in the fuse panel under the hood) is also in the horn control circuit too, so that's another possible culprit too.
If you don't have the expertise or equipment to troubleshoot the horn circuit, I would take the car to someone who does. The problem may be the horns themselves (unlikely as both would have to fail at the same time), the horn relay, a bad connection, or lastly, the horn contacts in the steering wheel (
). The first thing I would do is determine if voltage is present at the fuse when the steering wheel button is pushed and go from there.



Sounds like you need to take your car to someone to get the relay replaced or if you want to buy one and replace it yourself, the GM part number is: 12088567 It's worth a shot and hey, you need a horn relay anyway.
Just because the relay is missing, then replacing it doesn't automatically mean your horns will start working. They MAY or MAY NOT, depending on why the relay was removed in the first place. If it does not, then more troubleshooting will be necessary.
Go back to where you got shot down on your inspection and ask them to explain in more detail what they mean by "You need a muffler". That aint gonna hack it.
Ask them to explain or better yet, SHOW you where the problem is.
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Not only that, depending on what "you need a muffler" means, it may be something repairable at a muffler shop (broken weld for example).Take it by a Midas or whoever you like and have them take a look. Sure won't hurt to find what the exact "problem" is.
HTH









