I have a 2003 LB7 with a cali EGR and cat set up.. tuned with superchips and now a turbo back MBRP 4".

My friend has a 2001 LB7 no EGR no Cat

His truck with stock tunning KILLS my truck of the low end. His throttle respones is insane!

I'm baffled why my truck is such a slug...

About 110,000 miles I lost power also , the cat was stopping up ( could not see a flash light from end to end ) then at about 130,000 the injectors whent , runs fine now

About 110,000 miles I lost power also , the cat was stopping up ( could not see a flash light from end to end ) then at about 130,000 the injectors whent , runs fine now

I figured it was my CAT but just took it off and no such luck...

Try a fresh fuel filter and see what happens:)

what he said ^^^^ ..... these things are very picky about clean filters. makes a HUGE diference in mine when i swap it out, and i do it regularly every 10k.

I have an '03 LB7 also ant it is REALLY touchy and torquey at the low end.

However, as they said above, it is picky as all hell when it comes to fuel filters.

Could be the Superchips.

Could be the Superchips.

Tryed it with it off with no low end diffrence....

I did my fuel filter 10,000 miles ago I guess i'll invest in a new one..

The difference between my friends truck and mine is mind blowing! But once mine starts revving up it pretty equal...

could be the egr failing too. happened to a friend of mine.

Same here our 04 cali-LB7 started losing it's low end responsiveness lately, so today I unplugged all the banks stuff and loaded my ppe hot +2 off my LLY. Pretty much the same thing just way more power from midrange up. The fuel filter only has about 2k on it, so I do not think that is the problem. No codes thrown and I also removed the cat so I know that is not the problem. The turbo is spikeing at 34psi at W.O.T so I do not think it is turbo related either. Any ideas??

could be the egr failing too. happened to a friend of mine.


this will cause the truck to lose power?? how??

Same here our 04 cali-LB7 started losing it's low end responsiveness lately, so today I unplugged all the banks stuff and loaded my ppe hot +2 off my LLY. Pretty much the same thing just way more power from midrange up. The fuel filter only has about 2k on it, so I do not think that is the problem. No codes thrown and I also removed the cat so I know that is not the problem. The turbo is spikeing at 34psi at W.O.T so I do not think it is turbo related either. Any ideas??

Sounds like you are having the same issue! Makes no sence to me. All the tunner increase is top end... I don't have any turbo spikes...

this will cause the truck to lose power?? how??


Please explain this one. My EGR valve is disconnected I was thinking of adding a block off plate anyway

Sounds like you are having the same issue! Makes no sence to me. All the tunner increase is top end... I don't have any turbo spikes...

By turbo spikes I mean, what the turbo peaks out at W.O.T.

By turbo spikes I mean, what the turbo peaks out at W.O.T.

i'm assuming you have a PPE valve or something on the waste gate line?

i'm assuming you have a PPE valve or something on the waste gate line?

The lb7 has the banks big head waste gate on it, but the lly does not have a waste gate and will hit 34-36 lb's of boost at W.O.T with just the ppe hot +2 ET and has way more low end power and responsiveness then the lb7.

I believe if it was a egr problem ya'll trucks would be blowing more black smoke than usual. Have both of you changed your fuel filters yet? I had a run for about 3weeks were I went threw a fuel filter a week. Don't know if it was bad diesel or what?? Same symptoms though. The low end was pretty weak, but midrange and top end I couldn't really tell very much. I'd change a filter and it was like driving a different truck.

By turbo spikes I mean, what the turbo peaks out at W.O.T

Have you talked to dan about this? I believe this has happened to a few other members on the site. I remember Heavyhd having the same issue.

I believe if it was a egr problem ya'll trucks would be blowing more black smoke than usual. Have both of you changed your fuel filters yet? I had a run for about 3weeks were I went threw a fuel filter a week. Don't know if it was bad diesel or what?? Same symptoms though. The low end was pretty weak, but midrange and top end I couldn't really tell very much. I'd change a filter and it was like driving a different truck.

Alright i'm convinced i'm ordering a filter up as we speak...

Have you talked to dan about this? I believe this has happened to a few other members on the site. I remember Heavyhd having the same issue.

I did not know there was a problem with 34lb's of boost @W.O.T.

is that on the lb7 or lly? it seems a little high on an lb7. average high on stock turbo is around 23, 24 lbs. i dont know what the lly's make for boost.

Ken

is that on the lb7 or lly? it seems a little high on an lb7. average high on stock turbo is around 23, 24 lbs. i dont know what the lly's make for boost.

Ken

On the lly I know it spikes to at least 34lb's of boost, thats reading from the mechanical boost gauge as well as the ppe. The lb7 does not have a mechanical gauge but on the tuner it reads about the same boost as the lly.

hmmmmm. that seems a little high, maybe. but that could also still be in the safe range for the turbo. im not 100% sure on around what pressure the turbo goes kerplode! but i think im getting sidetracked from the no low end power.

Ken

maby try putting new clamps on your fuel filter lines, it worked for me