That larger tube is probably catalytic converter.
And ticking noise is normal. Metal is cooling down.
New VW Routan owner here... Thus far enjoying the van very much.
After driving the Routan for a bit, the exhaust will develop a repeating ticking sound (every 8 seconds or so). It's coming from the exhaust below the passenger side door (there is some sort of tube in that area that's larger than the exhaust pipe, I'm not sure what it's called). Has 9100 miles on it.
You can't hear it while in the car when driving, but if you stop and get out you can. After you shut off the engine it will do this for 5-10 minutes while cooling down, too.
Anyone else experience this? Is it normal? I listened under the car and can't figure out why it would make this noise...
This guy did, pour through his thread perhaps he found a soloution.
1958 VW Ragtop Bug
2005 VW Passat Wagon
2010 VW Routan SEL
Be sure to check out the Original Routan Dead Pedal Click Here