TRD Exhaust Hissing Sound

This has been going on for almost a year. The cat back TRD exhaust has been on it since purchase 2 years ago.

I notice a loud hissing sound when climbing a hill or at higher RPMs in general. Especially when driving along a guardrail. Seems to be definitely coming from the exhaust.

Never noticed it before that.

Any thoughts?

 

Do you see any black soot around the two bolt flange?

The flange bolts may be loose and the gasket has failed.

 

Ill definitely take a look at that. Thanks

 

Definitely sounds like an exhaust leak.

 

Exactly what I was thinking. Did a look around underneath but didnt see anything obvious. Maybe just overlooked the gasket

 

Get a sprayer bottle and put water and soap in it. Then spray all the exhaust connections with the motor on. If you see a big bubble form that means that's where your leak is.

 

Could this cause a power decrease? I noticed a bit of a power loss after the hissing started, might just be mental idk

 

Exhaust leaks normally have a sharp pfffdtt sound, or a brattt bratt sound.
You might consider checking your airbox and tubing before the mass air flow sensor as well. Intake leaks sound like a hiss or a shhhhhhhhhhhhhsssssss sound.
Just my two cents based off some words on a page.

 

Someone on the TT thread used a leaf blower on their exhaust tip. Just duck taped it on and searched for leaks.

 

If you hear a definite "Hissing" sound it could be a plugged converter, do you notice any degraded performance ???

 

That was actually my first thought. What are the odds of a 4 year old converter plugging?

 

Have someone hold a heavy rag over the tailpipe while you look under the truck with the engine idling in park -- with the hand brake on!

 

I knew I should have posted this earlier. You guys are always a big help

 

Check the gasket(s) at the exhaust manifold, then work toward the rear.

 

Was the catback TRD exhaust installed as an “aftermarket”? Odds are, a gasket wasn’t used (if it lasted a year, then there is a gasket) or it is bad gasket. You really don’t want to re-use old gaskets and also want to ensure the bolts are torqued properly or they could snap. It could be loose, causing it to not seal properly, thus a leak. If you installed it yourself, now you know. If someone else did it, I would have taken it back (1 year?!) and get the issue resolved.

 

Truck was a lease when I bought it so im assuming factory or presale dealer add on