anyone know whats wrong? ugh

[Miked5426]

ok. i got 3.0, 42 pounders

aem intake

1.75" primary zzp headers, high flow cat

i had a zzp tune, but it wasnt feeling right, so i switched to a more gm stage 2 tune

still having issues wth lack of power, pulsing, and knock when i hit the accelerator

I am posting my latest log. anyone know where to start??

[Light'balt]

Could it be an injector problem? Xen had a problem with his injectors. I was looking for the .cfg file that would pick up misfire's. I thought I had it but I remember Xen had the .cfg file. Maybe he can put it in the repository.

A flaky injector could cause the pulsing issue. Maybe one injector is not firing correctly or dirty maybe?

[IMADreamer]

you don't have an exhaust leak by any chance do you?

[XenSS06]

ok. i got 3.0, 42 pounders

aem intake

1.75" primary zzp headers, high flow cat

i had a zzp tune, but it wasnt feeling right, so i switched to a more gm stage 2 tune

still having issues wth lack of power, pulsing, and knock when i hit the accelerator

I am posting my latest log. anyone know where to start??

I have the 1.75 primary's Hi-Flow Cat with a 2.5 exit whats your exit?

here is my config i used when i thought that my misfires were a prob.

I just looked real fast your only getting knock from 768-2560 rpm's

Looks like your getting the same knock i was/am only at tip in, "knock when i hit the accelerator"

Have you checked for exhaust leaks?

Can you elaborate on the pulses like when and what your doing/rpm/afr?

The lack of power what are you comparing that to?
If your comparing you "lack of power" or maybe torque could be atributed to the more free flowing header.

[Miked5426]

I have the 1.75 primary's Hi-Flow Cat with a 2.5 exit whats your exit?

here is my config i used when i thought that my misfires were a prob.

I just looked real fast your only getting knock from 768-2560 rpm's

Looks like your getting the same knock i was/am only at tip in, "knock when i hit the accelerator"

Have you checked for exhaust leaks?

Can you elaborate on the pulses like when and what your doing/rpm/afr?

The lack of power what are you comparing that to?
If your comparing you "lack of power" or maybe torque could be atributed to the more free flowing header.

the lack of power feels like im pulling an elephant. i step on it...but it's just not going like i remembered it brand new. ESSPECIALLY WHEN ITS WARM OUTSIDE. (80+ DEGREES)
im not sure if theres an exhaust leak or even where it could be OR HOW TO DETECT??


my exhaust exit is a 3" and then shrinks to 2.5 after the cat....

the pulsing comes only when i accelerate with half or more throttle. once i hit over 3200-3500 rpm it kicks in and goes. so perhaps that may be attributed to a bad ve table or other tune stuff????

[Miked5426]

OK.. I checkd my headers. and there were two studs that were slightly loose. so i tightened em. but all the only were too tight to move. but i think i still hear a bit of air...or could it jus be the engine? its hard to tell

[fast cobalt]

its a cobalt thats whats wrong. lol

[IMADreamer]

What kind of boost are you seeing? Could be a cat issue.

[XenSS06]

Could be a fuel issue maybe a dirty fuel filter or dying pump.

[Miked5426]

no. i always replace fuel filter. and i did it twice before and still did same thing. i see boost upwards 15-17 max