Question : Engine Loud After LIM Gasket Job

[Huckleberry]

Greetings friends. New poster here.
I searched my specific issue, but came up with nothing,
so I joined this forum to see if I could get some authoritative help.

Just completed a LIM gasket replacement on our "02 Grand Prix SE 3100 SFI.
Used new manifold bolts as recommended.
Replaced plugs, wires, therm, and PS fluid while I was at it.

I used the Lisle pushrod tool to remove and reinstall rods.
I was very careful to make sure the same size rods went back where
they were supposed to, although there is always a chance I muffed it.
I didn't do any "adjusting", or "setting", I just put oil in the tube and stuck 'em in.

Got her all back together, she literally fired right up.

I didn't touch the exhaust system in any way.
Now the engine is louder, as if there is an exhaust leak,
and almost a backfiring sound when you let off the throttle.
Can't hear it at idle or coast, but when revving and accelerating,
it has a loud throaty sound that it didn't have before.
What have I done wrong?

Any advice or experience with this specific issue?

Thanks in advance!

EDIT: Oh, yeah, and the SES light was on before and now after the job.

[1988GTU]

cracked EGR tube possibly.

What code is it throwing out?

[Huckleberry]

cracked EGR tube possibly.

What code is it throwing out?

Thanks for the reply.
Haven't had it plugged into a diagnostic yet, so I don't know the code.

You're the second person who has mentioned the EGR.
That's the cylindrical gizmo that connects to the TB?

When I did the LIM gasket, I removed the plenum,
but left the throttle body and its components on it.

I took that assembly, along with the LIM and the valve covers,
down to the carwash and douched them thoroughly.
Then they were set next to a fireplace for two days before reassembly.
Maybe I damaged it?

Now what exactly is the EGR tube?
Is it cast into the assembly, or is it rubber or plastic?

[Huckleberry]

SOLVED Thanks to 1988GTU

cracked EGR tube possibly.

What code is it throwing out?

Based on your reply, I started searching out "EGR tube".
After looking at a few pictures, I remembered what that tube was.
I remembered disconnecting it from what I didn't know at the time was the EGR.
I didn't remember reconnecting it.
Went out to the garage, popped the hood, stuck my face in there.
Well, guess what? I'd forgotten to reconnect it.
Got her back together, noise gone.

THANK YOU 1988GTU!!!
Hope I meet you someday.
I want to buy you a beer.

[1988GTU]

Awesome! gotta love the simple fixes

Time to make my way to the j-yard!