Any thoughts? EGR maybe? Do the catalytlic converters clog? Truck has 95,000 miles. Fresh air and fuel filters. Seems to start and run fine but under load it blows black smoke and I have to put my foot in it a lot farther lately. No error codes...

 

think you got a bad batch of fuel and plugged the filter again? Maybe a MAF sensor? should have thrown a code for that tho. Are u running the stock filter setup?

 

Thanks for the reply. After I started noticing the power loss and seeing the excessive smoke I decided I was pretty close to needing a new fuel filter anyway so I changed it and it didnt seem to fix it. Everything is stock except for a K&N air filter element. I've run a couple tanks of fuel through it and tried some injector cleaner and it's is the same.

 

Is that an oiled filter I take it? Have tried cleaning the MAF with some cleaner from Napa or similar?

 

Yeah, it is an oiled filter. I'll try cleaning the MAF sensor. That's a good idea, thanks.

 

imo, you should go back to the stock or paper style filter, it is said to support near 500hp so unless you are putting down some big hp #s, it just not worth the trouble of having to keep cleaning the maf sensor.

 

Get rid of the k&n filter.. We did a dyno test of 5 intakes and filters on our 06 shop truck and the k&n actually built the least amount of power. But i would try cleaning the maf sensor since the k&n have a nasty habit of gunking those kinda thing up. And if you want a aftermarket filter i would look into a afe intake or a sb.

 

Scott is right the K&N oiled air filters are not good. They plug up the MAP sensor and can get into the turbo and could hurt the turbo.

 

Thanks for the info guys. I'm going to try cleaning the MAF tonight and if that's the problem I'll be yanking out the K&N and look into some of the options you guys mentioned.

 

I hope I'm doing this right... I have an 06 Duramax as well. Last night on the interstate I noticed I was losing some power. When I looked in my mirrors I could see smoke in the lights of the cars behind me. So today after reading several blogs I had the K&N filter recharged, and got some MAF cleaner from the auto parts store down the road. But engine light is still on and still have excessive smoke when accellerating?