jphurst36

So I just signed up for the forum and this is my first post so pardon the long winded explanation, but here it goes.
First off I have an 07 new body silverado 1500 5.3L.
I put an aftermarket intake on it (vararam) and after 4 years of owning the truck I finally got a smog notice. So I took the aftermarket intake off and installed the stock intake. Drove it approximately 2 miles to the smog shop and they guy tells me the check engine light is on and he can't smog it. I say what, it wasn't on when I was driving over here and I only live 2 miles away. He says, well I can't smog it, but I can scan it for free and tell you whats going on. I didn't get the code numbers, but there were 2 codes, bank 1 too lean, bank 2 too lean.
Frustrated I started to drove home and while driving home all of the sudden the service stablitrak, service traction control, stabilitrak off, traction control off indicators.
I've been doing a ton of research on the internet, but haven't found the solution. Yesterday I cleaned the MAF and intake then disconnected the battery to reset the check engine light. After 2 minutes of ruff idle all seemed well, no errors, no check engine light, nothing. Drover it around yesterday and to work this morning with no issues. I finally thought all was well until on my way home the check engine light came back on and shortly after that the rest of the error indicators came on 4-5 times within 5 miles.
I've never had an issue with this vehicle and really want to get this fixed fast before something gets damaged. All of this started after I swapped the stock intake back on the vehicle, it had been sitting in the garage so I thought maybe some dirt got sucked into the MAF and intake and cleaning that would fix everything because I haven't changed anything else, but that doesn't seem to be the case.
Any help would be greatly appreciated.
PS, i also checked for vacuum leaks, only 1 line to check and no leaks.

jphurst36

Okay so I went to a friend that has a scanner and only code P0171 Bank 1 too lean. Ran the truck for a while and finally P0174 Bank 2 too lean came up again, but was intermittent and only P0171 stayed locked on the scanner. Switched to the ABS portion and got code C0561.
All the research I've done says there is nothing wrong with the stabilitrak and this should be a vacuum leak or mass air flow sensor. However the scanner showed the mass air flow sensor updating real time, so I'm going to assume its working properly. I checked again for air leaks and nothing.
Has anyone ever figured these error codes out? I need some help here.

jphurst36

Guys where's the help? I haven't replaced anything yet because I'm not in the business of randomly wasting money on parts that won't fix the problem.
Can anyone help on this???

cleveland63b

im betting your intake is leaking vacuum anytime i've had a p0171 and p0174 theres a 90% chance the intake is leaking, and since you just swapped them i'd say its likely.

spray brake cleaner around the intake while its running and see if the idle changes

cleveland63b

actually since you have access to a scanner watch the stfts (short term fuel trim) while spraying the brake cleaner if it changes while spraying compared to not spraying its leaking

jphurst36

Thanks for the response. Any idea what the MAF should be reading while scanning? Okay, I will do that and let you know what happens. For my setup ther is only one interface, a rubber coupler from the airbox to the intake so its not hard to search for vacuum leaks. But, if its not a leak then I guess its the MAF???? When I saw the numbers briefly on the scanner I saw that it was registering and updating, but I have no idea if the numbers it was showing is what it should be for an engine sitting at idle. How do MAFs usually fail? Do they still pass data to the computer, but the numbers are off or do they typically just stop working?
Thanks for the help/suggestions.

in2pro

You will need to check along the intake manifold for the leak not just the air intake.... check for cracked and poor fitting vacuum hoses... the brake booster hose and grommet

cleveland63b

yea sorry i didnt clarify, its the intake manifold gasket i was referring to

jphurst36

Okay,
So I had to put the truck on the back burner and ride the bike to and from, but now I'm about to be screwed. My registration ends at the end of this month and I need to smog my truck so I can get it registered and I can't with my check engine light on.
I need this fixed ASAP!
So here's what I've done lately, I changed the MAF sensor, went out for a 30 minute drive, thought everything was good then as i was pulling into the driveway and the check engine light came on........so pist, so its not the MAF sensor.
I was finally able to borrow a scanner and here are the readings I just got off the scanner:
ABSLT TPS=15.3
BPM=592
BARD RRS GH=29.8
CALC LOAD=12.9
MAF=0.53 LB/M
MAP=9.4HG
COOLANT=192
IAT=111
IGN ADV=16.5 DEG
ST FTRM1=9.4%
LT FTRM1=29.7%
ST FTRM2=11.7%
LT FTRM2=29.7%
ABS LOAD=12.5
FUEL PRESS=44
REL TPS=1.6
THROT CMD=2.4
THROT POS B=14.9
ACC POS D=18.8
ACC POS E=9.0
CAT TEMP 11=891
CAT TEMP 21=880
EVAP REQ=13.7
EVAP VP (H2O)=0.2268
CMD EQ RAT=0.999
02S 1-1=0.11
02S 1-2=0.625
02S 2-1=0.835
02S 2-2=0.49

Do these readings seem normal? Anything that stands out as an issue?
Any and all help is greatly appreciated! Clock is ticking, I don't want to get a ticket for driving with an expired registration or get towed for expired registration.
thanks

cleveland63b

was that idling or going down the road? your fuel trims are high which means the pcm is trying to add fuel. did you try watching the scanner while you sprayed it? sometimes its tough to hear the idle change but the scanner will show it. According to that reading your fuel pressure is also low so i'd hook a gauge up and see if its actually only at 44psi.