Dpf trouble

[ltz2011]

Hello.

2011 model.

Have gotten "engine power is reduced" light.

Scanner show codes 

P24A0 

P0420

I tried dpf regeneration for several times and its dosent help. Its still soot.

The temperature  doesn't go over 300 Celsius +-. I cant know the exact number cuse i cant do regen and chack stat at the same time.

What could be wrong? 

Also glow pluge number 2 and 6 are not ok,dont know if there is connection to the dpf problem.

Thanks.

 

 

 

[ltz2011]

Also code p2463

 

[Bruce Alsup]

I had the same problem with my 2009 GMC Sierra 3500 HD.  Spent a month and $$$$ trying to get it right.

First, the regen doesn't work properly if the glow plugs are not working.  Have to replace those first, then try regen (or pay the GM garage $$$ to do it).

Next, the 2008-2011 models before DEF are not able to regen sufficiently if you are pulling a load through mountains.  Even with everything working properly.  GM should have done a recall but got away with it.  Only solution if you are going to haul loads in hilly terrain is DPF delete.

You can also remove the DPF and have it cleaned commercially (about $800).  This will work for awhile but only if you are NOT hauling a load.