OK, I give up... What is Regen? Explain please.

The exhaust filter starts to get clogged. So the motor needs to burn out the soot. Usually with a lot of highway driving and little idling the engine does itself while driving. However with a lot of idle or city driving it builds up and usually there is a light on the dash that tells you it needs to do a parked regen. That means you park hit a button and the engine revs up gets the exhaust really hot and burns it out.
I'm not great at these explanations, best I can do. I was surprised no one answered yet. Perhaps somebody else comes along to say it better.

 

Shoot, I thought you were talking about our 40th president! That's how much I know about regen. From what I've read it can make the truck run really rough while a regen is going on.

 

Regens started with EPA07. Many 07's do not have it, they were preorders from 06. It's just like Bayle said. There is a soot filter in the muffler called a Diesel Particulate Filter (DPF). When soot levels get high, the regeneration burns it out.

There are 2 basic types of regens, Active or Passive. Passive means that no fuel is injected into the exhaust system to add the heat needed to regenerate the DPF. This is when your highway driving and the engine is making enough heat. An active regeneration means that a fuel dosing valve injects fuel into the exhaust system to raise the temperature. An active regeneration can be automatic or driver initiated. The engine will always try to do it automatically, but if it cannot, a light will come on giving warning that a regen is due. At this point, the driver must change the duty cycle of the engine (get out on the highway and hammer down), or if that's not possible, pull over some where so he can do a manual regen. A manual will can take 30 min to over an hour sometimes, typically they are 30-40 min though.

 

they really suck. in the winter is when i get it. you wake up. ready to go drive. but the light is on. so now you get the luxuory of waiting for a regen to complete. before you can ACTUALLY start driving.

 

some guys seem to get trucks need them more then others
I only did 2 manual regens in 2 years
friend same truck 4 one week

 

Same as video games. When you flip truck and game over just hit regen and you get a new life.

 

You ever riding down the road and see a newer truck blowing out thin, blueish smoke??? The truck is going through a rolling Regen. Some trucks are worst then other, Cummins motor's to be exact...

 

Idle time plays a BIOG part in it. Friend of mine also has a '09 S60. He was doing manual regens pretty much weekly. I have yet to do one. He idled, I have had the generator from day one.

Martin