P0172 And P0175....

d_curtis3 · February 17, 2010

2008 Silverado 1500 4X4 82000kms

5.3L flex fuel w/AFM

Airaid intake and throttle body spacer

My truck is cranking long and starting rough, but once hot it runs fine and starts fine

A couple of weeks ago, went to start my truck and it cranked a little longer than normal, but started nonetheless, because we had a lot of ice fog, thought it might have something with moisture in connectors. truck ran fine, logged some kms that day. a few days later it did it again, checked for codes and there was a cam sensor code?? cleared that code and it never threw it again

peeled the hood back, and cleaned my air filter, then noticed that the intake tube had come loose right off the throttle body, not all the way off, but a gap at the bottom. tightened all that jazz up, now the truck still cranks long and starts rough, but once hot same story.

Now it's throwing a P0172 and P0175 code at me, fuel system too rich on bank 1&2. i clear the codes, and they come back after a while

Air filter cleaned

MAF checked, clear

Left battery unhooked over night with hopes of clearing computer

I'm in the process of checking my spark plugs right now,3/4 on D/S have looked.....ok....(carbon buildup but not MAJOR) 3rd cylinder back on drivers side was wet and still had the smell of raw fuel, also was covered in major carbon deposits

I'm going to check all my plugs and look for any obvious signs, and hopefully i find one, will likely replace spark plugs just for the sake of knowing.

Not sure what else i should check, i'm at work for a while yet, and not able to leave it at the shop right now. So any suggestions are greatly appreciated. Thanks

d_curtis3 · February 17, 2010

update, just pulled all the plugs, all except the 1 were slightly blackened, no others had all the raw fuel on them. what could be causing my rich condition?

i've checked all vacuum hoses, cleaned MAF connector. i havent noticed any consistency to when the CEL will show up, yesterday it popped up shortly after starting, a couple days ago it was after i had been out for a drive (45minutes) and was backing into a parking stall. before that it was after being running for ~15 minutes.

is it possible that after my intake was off for a while, it started giving less fuel because it didnt think there was any air coming in, and now that theres "way more air coming in" (now that air is coming through MAF again) that it thinks it needs wayyy more fuel? i'm grabbing at straws here.

Thanks again

p.s. sorry if my posts are long winded

UPDATE: Truck barely started just now, took 4 tries, cranking about 6sec each time, and even then 4th time barely started after feathering the throttle. I've got a bottle of injector cleaner in a tank of premium that i'm going to burn through it before i replace the plugs.

running out of ideas

MaForrest · February 20, 2010

I am using the same air intake as you. My truck was doing the same thing that yours is from the sound of things and it was my MAF. It was way way too dirty even though I couldn't tell it was untill I started blasting it is MAF cleaner. Then didn't let filter set long enough and had too much oil on it and screwed it up again. Mine was running lean though, showing too much air and cut the fuel back. It could be alot of things really, I aint no mechanic but I would suject taking it to get a diognostic check run on it and that way they can hook your truck to a computer while its running and see exactally what its doing.

d_curtis3 · February 20, 2010

I replaced plugs yesterday, and cleaned my MAF with electrical contact cleaner. no better this morning, i'm working on putting some videos up on youtube so somebody can understand exactly what i'm going through

d_curtis3 · February 20, 2010

http://www.youtube.com/watch?v=2Zv0UX2_y3s

this one is truck cold start.

http://www.youtube.com/watch?v=mve27X7QcmI

this is after it warmed up for 15 minutes

desrtrat · February 20, 2010

when was the last time you cleaned your TB? i would also check for a vac leak. your injectors could also be dirty. try running some Sea Foam thru your tank and see if it helps..also remove the TB spacer. if all else fails, take it to a dealer under your power train warranty and let them fix it..

good luck..

EDIT..i read somewhere that on the newer trucks were having issues with new CAI, and not running properly. i can't remember the make, but the issue was the MAF/ air temp censer not seating properly in the tube..

d_curtis3 · February 20, 2010

when was the last time you cleaned your TB? i would also check for a vac leak. your injectors could also be dirty. try running some Sea Foam thru your tank and see if it helps..also remove the TB spacer. if all else fails, take it to a dealer under your power train warranty and let them fix it..

good luck..

EDIT..i read somewhere that on the newer trucks were having issues with new CAI, and not running properly. i can't remember the make, but the issue was the MAF/ air temp censer not seating properly in the tube..

fancy you should recommend that, i just got back from the dealership, seeing about getting it booked in, bought some TB cleaner to give it a good scrub, and a can of seafoam. i put some of it in the oil and i'll dump the rest in the tank when im getting closer to empty. i can't hear a vacuum leak anywhere.

i too read something about the MAF not being in there properly, i've had it disconnected probably 3-4 times over the past couple weeks, i would hope i got it right one of those times lol

Thanks

d_curtis3 · February 21, 2010

removed and cleaned Throttle body yesterday, cleaned MAF with CRC sensor cleaner, removed throttle body spacer, cleaned as far into intake manifold as bottle brush/rag would reach.....inside of intake was oily, with a small pool in one low spot. normal? so this morning i went out to start the truck, -18*C on the thermometer. this time when starting it, i blipped the throttle a couple times while cranking, and it started within 2-3 seconds, ran rough like it has been, and then smoothed out after about 45 seconds.

I'm going to run the rest of my seafoam through the gas tank, i've got about 3/8tank left. think this route might be a lost cause, but oh well. doesnt hurt to try

if this doesnt fix it then i guess i'll have to suffer and leave it in the shop for a day or two, and powetrain warranty it like desrtrat said.

i'm wondering if the intake tube came off as a result of a backfire?

and 1 more thing, i just realized how terrible the Airaid intake fits on this truck when you don't have the throttle body spacer installed.

Cheers

brims · February 21, 2010

You should change the oil, get that Sea Foam out of the crankcase, most recommend not putting it in the crank case, and those that do recommend an oil change soon after.

d_curtis3 · February 21, 2010

the small amount of seafoam that is in there has only been in for about 18hrs

d_curtis3 · February 24, 2010

just checked my codes again and i have a P1175. have a read of this....seems to fit the description of my problem. anyways, it's going in to the dealership tonight and they can deal with it from here on out

Thanks for the replies

http://gmdesolutions.net/equipment/tsb_pdf/afit_bulletin.PDF

gord8873 · March 27, 2010

What did the dealership end up doing? I've had the same codes as you since I bought my truck, but they never find anything wrong. Mine only seem to happen in the winter, and when the engine is going from V8 to V4 mode.