What to do?

[kinjo1977]

Alright.
So I go out and start my truck, and each morning I swear the exhaust gets louder and louder. In fact, I have went from a low rumble in the cab to a loud drone that vibrates the little plastic piece behind my seat. Also, this past week and a half, I have noticed a shaking in the cab as if the engine were slightly rocking side to side. You know that side to side motion it gives when you first start up, well it doesn't stop in my truck till I am going for a while. And to add to all this, when going up the interstate at around 75, I noticed that when I speed up to 80 or so the power just leaves. It's like it won't give me any more power after 75 unless I stomp it. So what do you think could be causing this?
Could it be an exhaust leak I'm not noticing?
I looked under the truck and inspected the piping, but all I noticed was some black carbon build up around the connection of the y-pipe to the inlet of the muffler.

Here's a pic of the y-pipe connection:

[chrisj6]

I dont think there is a gasket in these connections, but it does look like there is an exhaust leak. When you go out and start the truck in the morning, try to feel around that area and see if you can feel the exhaust leaking.

Chris

[RedHeartbeat]

Yep, serious leak there. If you have a 02 sensor down stream from that leak you will be introducing fresh air into the exhaust stream and the PCM will screw up your fuel mixture.

[kinjo1977]

Serious??
Hmm.....I don't think there are any O2 sensors past that. But I will check in the morning.
Would that cause bad gas mileage?
Should I try to tighten those bolts or just wrap it with some heat shield tape?
Or, worst case scenario, replace the y-pipe?

[RedHeartbeat]

Definitely will cause fuel problems if you are sucking in fresh air and an O2 sensor reads the normal reading before the leak and oxygen mixed in after the leak.

[kinjo1977]

Any idea what is causing the engine shake? or power loss?

[TXsilverado]

sry to hijack, but if an exhaust leak can reduce hp and gas milage why does everyone get cut outs? that just sounds like a huge exhaust leak to me...

[RedHeartbeat]

Lean fuel mixture. Get the exhaust fixed. The engine can sometimes hear/feel the exhaust leak thinking its a knock. Most cars will run poorly if the exhuast is in disrepair.

[kinjo1977]

New y-pipe and all?
If I gotta replace that I might as well just rip off this old flowmaster and put on the hooker aerochamber I was wanting.

[agreif]

A long shot on an 00, but sometimes clogged cats can give you a hefty power loss too if they are clogged. Woudln't think that would be the case with a truck as new as yours though.

TXsilverado, my basic understanding is that with any type of forced induction the engine wants to breathe, so the cutouts help that, but with a NA engine I am under the same impression you are, performance falls to the floor. Someone will correct me if I am off on this.

Andrew