Cm870 black smoke

[3406E]

Cm870 800+k miles. 04 engine. Should my pipes be that black? Egr not deleted. I doesn’t have smoke at idle but when I hit the throttle going down the road I do get some smoke but not drastic but I can see black smoke when im pulling hills and again not drastic like a turned up cat. The question is why is both my pipes so black. Image down below. Thanks for your help. And to add this truck is bone stock at 475 governed at 65.

[3406E]

I also don’t think the previous owners did overhead on it, truck is kinda lazy over hills aswell have to drop way too many gears. I was running same load with my buddy to Texas from Georgia and he was toying with me on the hills all time. He’s running 12.7 Detroit @500.

[Rawze]

Having a bit of some some black smoke when shifting gears hard , etc. is about normal for a CM870 . but it should not be smoking after it settles.


As far as it feeling laggy, put it on a dyno. Make sure the power matches the dataplate within 85% ... and that the turbo is not hanging up.

[3406E]

Ok thanks for the reply.