L5P Excessive regen

ikeG

Oughta Know Better
Apr 19, 2011
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Western PA
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I have a 6500 rollback in here with several issues. Took care of an in tank fuel pump issue. Then had a P2459 excess regen DTC. Service regen finishes successfully. But test driving, it blows black smoke under hard accel and 1 or 2 injectors will fuel knock pretty bad. It sets no codes currently but it did its own regen during my last drive, right after the successful service regen. Truck as 165k on it. Im just wondering what to chase first. Is the injectors leaking enough fuel to overload the dpf or is a bad dpf causing the fuel knock. Or all of the above lol.
 

2004LB7

Super Moderator
Staff member
Dec 15, 2010
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Never heard of a DPF causing a fuel knock. I'd guess injectors before DPF

How's the balance rates?
 

2004LB7

Super Moderator
Staff member
Dec 15, 2010
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Could be a clogged cat. Seen that one before, no power or codes just smoke.
I've seen that but without the extra smoke

My LB7 before the weight reduction. And on my LMM DPF before I figured out why it wasn't regenerating. Both didn't put out any additional smoke when clogged up. Very low on power. My LMM actually started to have turbo surging and was leaking out of the gasket down on the exhaust with the excess pressure.
 

ikeG

Oughta Know Better
Apr 19, 2011
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Western PA
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Customer pulled the plug when I showed him the main ned rail broken off. The main one that runs the length of the bed and rides on the frame of the truck

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