What are they for?
 

This is a question maybe for the grandees of Chrysler Enthusiast Forum:

In my diesel 2.8CRD GV, I've counted three boxes in the exhaust system.
1) A rear round box as far back as anyone could get it, positioned left to right.
2) A large semi-cubic box just ahead of the rear wheels, UKdriver's side, positioned fore and aft.
3) A semi-vertical 1st. box leading to the back of the engine.

Thanks in anticipation,
Leedsman.

I don't know the answer Leedsman, but I do know that when the Stow 'n' Go was introduced, Chrysler had to make significant changes to the exhaust system and the spare wheel location to make room for the storage bins that the seats fold into.

Thank you so far...
Despite a recent MOT showing low particulates/soot emission, the tailpipe seems very sooty. I've a feeling in my bones there could be something wrong in the exhaust system.
This is why I need to know what each box in the system does. The semi-cubic one does seem unusually large.
I've had a little wrestle with the spare wheel when I first got the motor, not a fun thing at all. Surprizingly, the spare wheel was fully blown up to spec.

Leedsman.

No 3 is the cat, 2 is the silencer, 1 is the resonator ( which changes the tone of the exhaust by bouncing sound waves around)

Regards
Richard

Of course no 3 will be the Cat. My 2.5crd exhaust is a one piece from cat back with both boxes inline.

Thanks Tfb and Goggs, do either of you know if the catalyser has a service life?

Leedsman.

You should get a generic P0420, if your not getting both the P code and a warning light I'd assume its functioning within efficiency parameters. The individual service life depends on country, heat, mileage, type of use, a whole combination of differing inputs - we are all going to be different.

rod it out ;)

Richard

Thanks again, yes, I've considered smashing out the catalyser too, and replacing it, to look as if nothing has happened. But before doing such a job, I need to be sure of my grounds. I'd prob. pay someone else to do it as it's in such an awkward place.
One thing is puzzling me, some of the various suppliers of these exhaust systems describe the catalyser also as a DPF. This is hard to understand -- a DPF that has no regenerating cycle? I'm suspecting this is not a DPF at all, but only a catalyser. Or is it that I'm not noticing a regen. cycle because it's done by the post main injection system?

Leedsman.

A CAT and a DPF are not the same thing.

- a CAT is a flow through the end “soot trap” it cleans itself by active or passive regen by spitting its own crap back into the environment
- a DPF is not a flow through the end but a forced through the walls device leaving the remaining soot trapped forever in the walls of the CAT

Its not illegal to drive without a catalytic converter but most vehicles will also fail an MoT test without a catalytic converter. Worth £50 to £200 depending on the size and mileage done they are a new target of 'hacksaw' theft.