The Ford "Chug" Sound And Exhaust Smell

[Turboguy]

Anyone who's owned lots of Fords knows the Ford engine "chug chug" sound at low rpm.

My 140,000 mile LS is chugging louder now for some reason, and if I don't hit the recirc button for cabin air when starting car, it blows exhaust smell in.
I recently had the intake replaced, but problem didn't start until months after that. Otherwise car runs perfectly, no codes, new cats and O2 sensors et .

What could I check that would cause this sound and smell?

 

[Telco]

Might check for a cracked exhaust manifold?

 

[LS4me]

Anyone who's owned lots of Fords knows the Ford engine "chug chug" sound at low rpm.

My 140,000 mile LS is chugging louder now for some reason, and if I don't hit the recirc button for cabin air when starting car, it blows exhaust smell in.
I recently had the intake replaced, but problem didn't start until months after that. Otherwise car runs perfectly, no codes, new cats and O2 sensors et .

What could I check that would cause this sound and smell?

I've had Ford products exclusively for the last 27 years and have no idea of what you speak.....

 

[Turboguy]

Hmm, I'll check that Telco.

In my experience with Fords they make a distinctive sound. Dunno if it has to do with firing order or ? But ours like my LS and our old 1980s F-150 both do it.

 

[2002_lincolnLS]

get under it and see if you can move the exhaust up and down. Mine is the same way due to loose studs (where cat and manifold connect) i need to replace mine due to being completely frozen up and will snap if I try to tighten