Scanningr for codes
 

When I scan the computer where it shows ready to fire and all that, two lines show 025 and H025 not ready. Could this be a problem with the tune ( I am battling P0171 and P0174 codes) or is it something that was deleted? Also, does anyone have the part number for the vacuum port for the brake booster on a 2007 4.8. I would like to replace mine to eliminate a possible cause for my supposed vacuum leak. Thanks, Tbrown

Re: Scanningr for codes
 

Passenger side of intake manifold on side of top chamber is a vacuum port usually used as a blend door vacuum source....

If you dont need it, just plug it...

What vacuum ports are you wanting to add? Power brakes ?

:chevy::chevy::chevy:

Re: Scanningr for codes
 

I am using that port for vacuum wipers. Not trying to add anything, just trying to find vacuum leak or cause for P0171 and P0174 codes. I have power brakes, and just want to make sure the swivel on the booster port isn't leaking vacuum.

Re: Scanningr for codes
 

It's rare for the booster port o-ring to leak, Intake gaskets are common & the intake itself being cracked is very common on wreaking yard engines.

Re: Scanningr for codes
 

Temporarily block off that port to test...you may have vacuum wiper feed leak...

As clinebarger said...intake gaskets and intake manifold leaks, especially under the manifold...

Re: Scanningr for codes
 

Already changed the intake gaskets, but will block off that port and try it. Thanks for the help.

Re: Scanningr for codes
 

If the O-ring is leaking.....There really isn't a way to block it with the quick release mechanism & all.

Though your booster may be leaking.....Clamp/pinch the booster line to confirm.

Can you watch live Fuel Trim Data?? A vacuum leak will show as high trim corrections at idle & correct under acceleration.

Normal trims at idle & positive corrections under acceleration would be a fueling issue. (MAF, Injectors, Fuel Pressure)

Re: Scanningr for codes
 

That is new information to me, I will check it out. Thanks

Re: Scanningr for codes
 

Also make sure your pcv on the valve covers are hooked up as this will throw the codes.

Re: Scanningr for codes
 

Subbed for new knowledge......

Re: Scanningr for codes
 

they do sell a plug that will go into the booster hole(used on trucks with hydro boost) spot no longger sold by gm they are a dimond in the rough if u find one everyone wants good money for them i got lucky and soeone here on the fourm sent me one since im using manaul brakes still