You can do a forced cat cleaner with ODIS and probably VCDS too.
This increase the exhaust temp to burn off residue on the cats.
This happens on regular basis, but it will not tell you when. You can both smell and hear it if you stop the car right after a cycle.
Larger engines, as in wheel loaders etc, will prevent you from turning of your engine while regenerating.

 

I assume you mean you can hear the fan running after stopping the car and switching the engine off?

 

The only time I can hear the tick-tick of a very hot exhaust on a diesel cooling is when I also can smell the “burnt rubber” smell associated with the regen.

 

Yes, that I recall as well, but most of the time it was (at least as far as I recall) also associated with the radiator fan kicking in when the car is switched off. I wonder if these two are related in any way. I can remember in the good old times of Gold TDI I used to own the same thing would happen.

 

I would believe the fan should be running as well, things are hot

 

Thanks guys for the valuable information, however I still didn't get an answer to my question. Are Cat. Con. or complete fuel system cleaners safe to use, and are they actually beneficial in any way? I don't have access to either ODIS or VCDS at the moment.

 

I have not used them and no opinion. It's like with vitamins you might be taking can you prove they help really? I'd they do you don't get sick but if you don't you might not get sick.

 

A CAT is NOT the same as a DPF, and as such, I'm not sure what you guys are suggesting will be done with a VCDS.

 

Thank you. And as my car has the 3.6 gasser, the info about DPFs, while interesting, is not really relevant to my case.

 

Why are you thinking your CAT needs cleaning?

 

No particular reason. I try to adopt a "preventive maintenance" policy, and since the car has over 200k km, I thought it wouldn't hurt to do some cleaning.

 

Look up how cats work... they don't need cleaning. They typically only clog if the internal honeycombs break down\rot and create blockages.... but if you had those issues, you'd be popping CELs and such. You need to have a bad running engine, burning all kinds of oil and stuff to clog up a cat, and even then it isn't easy.

 

I see. I appreciate the clarification. Guess I won't bother then as the engine seems to be running well and the exhaust pipes don't have any odd residues of any color.
I have noticed a clearly audible sharp "whistling" sound coming from the engine compartment and I'm not able to locate its source, so I'll have my mechanic check it this Saturday. Hopefully it's nothing serious. I expect maybe some kind of vacuum hose leak somewhere.

 

Well, whistling sound found, just some vacuum seal needed replacing. However, while in there, the mechanic discovered that the valve cover was cracked 😭

So, I did some quick research, and found the cheapest oem valve cover at fcpeuro for $355. on ebay it was a different story. Valve covers ranging anywhere from $30 to $80 can be had. I know. I know. You get what you pay for.
Anyways. Any suggestions? Comments? Advice? Are there aftermarket brands that are as good as oem that I can consider?

Thanks..