Sudden change in muffler sound

[ljy1990]

Hey guys, I got a new muffler tip installed around 2 months ago. Back then the sound was very deep but after I came back from a road trip, I noticed the sound of my muffler has changed from a deep sound to a bit higher pitch vibrating (fartish) sound when my car revs up. Like between 0.5-2 rpm it remains constantly deep but once it hit around 2.5-3 the sound changes from the deep sound to like a deep "farting" sound lol! (can't think of any other ways to put it). I never had this problem during the first 2months, is this because of the road trip? Because I was on the higway where my rpm would remain constantly on around 3.5-4rpm at gear 5 going at around 100-120km? I drive a Crx del sol 94. I noticed that my car also tends to run a little rich as well, could this also be the cause?
Just curious on how I may be able to change the sound back to the pure deep sound, has anyone else experienced this problem before?

Thanks in advance

[onevia13]

i know you said tip
but is it a cheap brand of a muffler?
one problems with those cheap ones are

inside the mufflers are filled with high temp acustical suppressions material for maximum sound absorption(well built mufflers).
cheap ones after a while(month/s, sometime weeks) just burns off, leaving you with high pitched funny sound. some worse ones ive seen even the even the "stainless steel" cylinder that also keeps your material in place inside the muffler, was all corroded

either than cheap mufflers, dont know dude...sorry
unless youve damaged the muffler when installing the tip

[squishy]

you might have an exhaust leak

[ljy1990]

Actually yeah I did get the tip for a cheap price, was recomended by a friend to buy it off a online store on eBay called options Australia? Could that be the reason why the sound is failing atm?
If so could you recommend a reliable manufacturer?

[ljy1990]

you might have an exhaust leak

In a way my car does show some symthoms of an exhaust leak, as in when I start my car in the morning, I do smell a but of gas, but I thought that was normal? Like the smell goes away once it is completely warmed up..
Should I get it inspected just in case?

[androo]

A lot of the cheaper exhausts use fiberglass to deaden the sound - Fiberglass breaks down fairly quickly due to all the heat. I had the same issue with my old exhaust. Moral of the story? Buy a proper one =]

Sorry to hear it though... We live and learn though ay?

[EKVTIR-T]

Yup,could be the internal packing material burnt away as the cheapo mufflers often do

You can add another mid muffler to tone it down or just replace the current rear one with something of higher quality

[Zilli]

if you only bought the "tip" which is the pipe that protrudes out of your muffler right at thevery enf of the system, i guess someone welded the tip to the muffler?

If the welds were of poor quality, they may have blown out cuasing a leak