iKevin

I have an Precision Muffler auto axelback installed and everything has been running great. The exhaust note has been a good balance between loud and subdued. But this morning I get in my car and it's really alot louder. Anybody ever have this happen?

Note: The exhaust is only about 3-4 months old and the car only has 3000 miles on it so I don't think the exhaust somehow burned out from sitting in the driveway overnight.

06ShadowBoX

the packing inside the muffler settled. (it broke in)

CHPRBOX8

^ I think that this is right

iKevin

wow . . big difference. Also it appears to get louder as the engine warms up. This go along with that?

CHPRBOX8

yes it dose the exaust should be the loudest once the car is at opperation temp

iKevin

I was thinking maybe my catalytic converter had pooched. Any way to know if it's toasted or not? Or would that throw up a light on the dash?

Ghost_1

If it is extremely loud check the exhaust clamp where the axleback goes to the OEM piping. Worse case scenario get in touch with Stylis on SL here and see what he can tell you about it. Hell he probably built the damn thing lol. Honestly though, I think you either have an exhaust leak or it's breaking in like everyone says.

Frosty355

Maybe someone stole the silencer out of the end.

BuddhasTC

if it's noticeably loud...it's probably an exhaust leak

Jhhnn

Yeh- check for an exhaust leak. It really shouldn't get louder suddenly unless something has gone wrong- loose clamp, cracked weld, something like that.

As the exhaust cools, it moves around a little, revealing hidden problems... Glass pack mufflers do get louder over time, but not suddenly- it's why I don't buy 'em...

vintage42

It may get even louder as the packing degrades more over time. The glass packing fills up with soot, gets packed tighter, fibers break up and get blown out. Glass packs are straight through, so they are compact and cheap to make, but do not remain the same as they age. I would prefer a reverse flow internally baffled muffler like the TRD.

iKevin

Checked for exhaust leak last night and all was well. After listening to it, it appears that it's probably just either that the exhaust has just broken in or the engine. Because I also noticed that it appears to have a little more power.

Avodka14

Keep in mind, your exhaust will be more vivid and louder sounding during night and morning times because of atmospheric conditions and less people being out (meaning more noise to be heard) by your car and in your situation, your exhaust. It is just basic physics, less absorbing materials such as less reflection of sounds running into other sounds. The other variables are what people mentioned above. I had an exhaust leak at my manifold/engine area and you will know in that area. It sound like a lawn mower putting and you can smell exhaust fumes really well. I got really lucky because it did not melt the manifold on my engine.

vintage42

How a manifold that conducts the exhaust be melted if there is an exhaust leak?

Avodka14

As the header mates with the motor an unsecured manifold can cause hot exhaust fumes to melt the exposed engine where the exhaust should be directly vacummed. Come on now, that is common sense

NC_Pinz

Sorry but that doesn't make a bit of sense. Vacuumed? Exhaust is under pressure. The exhaust is not hot enough to melt anything other than wire insulation or a plastic part.

frogbox

Makes perfect sense , you ever do any welding? use a propane torch? how about a bunson burner in hs science?

hot exhaust under pressure, from a small leak acts just like a welding torch,propane torch and/or a bunson burner. it will melt it away, metal,plastic, paint, anything in the flames path.

Avodka14

What do you think the aftermarket headers are designed for then? They act as a pseudovacuum as to suck air out of the motor or decrease pressure. I agree, the air going into and out of the motor is a pressure gradient and that is exactly how turbos work (exhaust pressure). Anyways, my terminology was not exact above. Do you know how hot exahust temperatures get? They can get up to 1200 F and that has been known to damage pistons and in my previous scenario the heads on the engine if I did not replace my head gaskets and my header as it MELTED SLIGHTLY made the exhaust leak worse! Not trying to start beef just wanted to justify that I am not going to be patronized when I know what I am talking about. No hard feelings bro.

metal112524

Technically there is no such thing as suction just a lack of pressure. If by vacuumed you mean moving from the high pressure of the exhaust to the low pressure of the atmosphere your first statement is 100% correct as Exhaust to atmosphere = high to low pressure area = in a sense a "vacuum"

vintage42

Is is true that some people have had the back of their engine melted by the hot fumes of an unvacuumed leak at the unsecured exhaust manifold?