SOLVED! Codes p0117, p0172, p0175

MBS1994

Original poster
Member
May 26, 2019
326
Colorado
Hello again and sorry if it's in the wrong section! So in getting a low voltage to temp sensor, running rich to bank one, and running rich to bank 2. I saw a write up on a SS forum that the rich condition could be a whole list of reasons including a faulty temp sensor. I had to repair my temp sensor harness before because I wrecked it doing my long tubes. I'm thinking the low voltage to temp sensor is triggering the rich condition. I have the pcmofnc tune, deleted rear o2s, just recently installed hiflow cats, front o2 sensors, e fans, dropped my driver side headers and pulled my plugs to try and repair broken off manifold bolts at the same time as the cats (had oil on a plug, most likely a leaking valve cover.). It started shortly after all that when it randomly started having a slight hard time to start. Only other thing I've noticed is it will sometimes feel like a slight hiccup at idle but my rpms dont move, just my battery volts dropped a little during it.
 

mrrsm

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Oct 22, 2015
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Tampa Bay Area
Addressing the P0172,and P0175 Codes involves considering Two Problems:

(1) A Dirty Mass Air Flow Sensor (YES... Even in the Absence of the P0101 Code indicating a MAF Sensor Problem)...the 2nd Video explains WHY to look at it WAY UP FRONT in the Engine Bay):

You live in the Higher Altitudes with Lower than Sea Level Air Pressure AND perhaps frequently drive in near Desert or Dusty conditions. This can make for the sooner-than-later accumulation of Dust and Dirt inside of the MAF Sensor. CRC Makes the Solvent that is exclusively used to Clean the MAF Sensor Screen and Internal Sensor Wires:

CRCMAFCLEANER.jpg

Jimmy from 1ROAD shows his generic, but successful experience (along with SAFETY ISSUES covered) on how to Clean the MAF Sensor with this Stuff:


(2) A Clogged Air Filter (Do you have an After-Market installed on your Trailblazer?)

Considering the presence of all your other Performance Mods, If you have an After-Market Air Intake Filtration System like the ones K&N offer as the Top Of The Line version... infrequent cleaning of that Filter can cause the Oil Soaked Fibers to almost completely clog up enough to Restrict the Flow of Air. This Video covers the same Engine Platform, albeit on a Chevrolet Avalanche with the 5.3L Engine, but shows how to deal with the issue using K&N's own Cleaning Products and K&N Filter Oil. The VOP (Video Original Poster) also recommends Cleaning the Throttle Body Intake Butterfly and inner areas of Dirt and Oily Carbon Build Up to complete the improvement of the "Air Flow Circuit":

 
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MBS1994

Original poster
Member
May 26, 2019
326
Colorado
Thank you for the reply and sorry for the delay. So not much of an update but I fixed my thermostat wiring last week, cleared all codes. After some driving and cleaning my MAF and throttle body yesterday as soon as I started it check engine light was back (p0172 and p0175). I cleared the codes again and will see if they stay off since everything is cleaned
 
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Maverick6587

Member
Dec 16, 2018
730
Sterling Heights, Michigan
Do you happen to have a scanner (cheap or not) that you can hook up to get the freeze frame data or even live data?
 

MBS1994

Original poster
Member
May 26, 2019
326
Colorado
172 and 175 are back. Maf and throttle body were cleaned and codes reset after. Also notice my battery volts like to dance when I'm sitting still. Dont know if they could be related
 
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Maverick6587

Member
Dec 16, 2018
730
Sterling Heights, Michigan
Did you unplug the battery for at least 30 minutes during/after cleaning the throttle body? It needs to be done to reset the throttle body.
 

MBS1994

Original poster
Member
May 26, 2019
326
Colorado
No not during but I went to the part store and they reset the codes for me twice now and it came back today for a third time
 

Maverick6587

Member
Dec 16, 2018
730
Sterling Heights, Michigan
I don't think resetting the codes codes clears the ECM data log of your throttle body. I'm pretty sure you have to unplug the battery for 30 minutes still.
 

MBS1994

Original poster
Member
May 26, 2019
326
Colorado
I don't think resetting the codes codes clears the ECM data log of your throttle body. I'm pretty sure you have to unplug the battery for 30 minutes still.
I will try that next. Also thinking clean my air filter but just surprised because it's only around a year old.
 

MBS1994

Original poster
Member
May 26, 2019
326
Colorado
Had my battery unplugged for around two hours and codes still came back. I had a thought today so I checked my tune sheet and notice it has egr and AIR (secondary air injection pump??) Deleted. I've been reading and doesnt seem we have a egr on these 5.3 06s but what about the AIR? could that be why I'm running rich?
 

Maverick6587

Member
Dec 16, 2018
730
Sterling Heights, Michigan
Before we start talking about just swapping out parts. I think it might be time to grab yourself a cheap scanner so we can see some live data and more accurately point to what could be the cause of it running rich.

Almost any ELM327 scanner will do. Hopefully you have an Android device handy that you could use. I think there are one or two iPhone apps that work as well with the ELM327 scanners. They're anywhere from $8 all the way up to $200 on most websites. Just depends on what you want out of it but, even the cheapest one will give us the live data we need.
 

MBS1994

Original poster
Member
May 26, 2019
326
Colorado
Before we start talking about just swapping out parts. I think it might be time to grab yourself a cheap scanner so we can see some live data and more accurately point to what could be the cause of it running rich.

Almost any ELM327 scanner will do. Hopefully you have an Android device handy that you could use. I think there are one or two iPhone apps that work as well with the ELM327 scanners. They're anywhere from $8 all the way up to $200 on most websites. Just depends on what you want out of it but, even the cheapest one will give us the live data we need.
Okay I ordered one and it'll be here Wednesday
 
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Mooseman

Moderator
Dec 4, 2011
25,257
Ottawa, ON
Had my battery unplugged for around two hours and codes still came back. I had a thought today so I checked my tune sheet and notice it has egr and AIR (secondary air injection pump??) Deleted. I've been reading and doesnt seem we have a egr on these 5.3 06s but what about the AIR? could that be why I'm running rich?

Talk to the tuner as the V8 doesn't have either. He could also have some insight as to what is going on.

It is possible that with the faulty temp sensor it will run in open loop and run rich. Fix that first and go from there. Have you tried replacing the sensor? If so, you'll need to check the wiring some more.
 

MBS1994

Original poster
Member
May 26, 2019
326
Colorado
Talk to the tuner as the V8 doesn't have either. He could also have some insight as to what is going on.

It is possible that with the faulty temp sensor it will run in open loop and run rich. Fix that first and go from there. Have you tried replacing the sensor? If so, you'll need to check the wiring some more.
The sensor has been replaced and the p0117 is gone so my temp sensor is fine I think. I have yet to contact pcmofnc because I've bombarded them a whole lot in the past with questions so I'd like to try and clear it assuming my tune isnt the problem
 

MBS1994

Original poster
Member
May 26, 2019
326
Colorado
So interesting development. I noticed a leak in the line from the top middle of the intake manifold to the driver valve cover. Fixed with a rubber line for now, idled for a little bit and it seemed smoother, went for a drive for the hell of it and noticed my check engine light was off. Dont know If that was the problem but at least at the moment my codes are gone.
 

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MBS1994

Original poster
Member
May 26, 2019
326
Colorado
I passed emissions so I suppose we can mark this as solved. It still showed codes on the log sheet but no check engine light so I'm assuming I haven't driven enough to clear the ecu data. Either way it's good for at least a year. Thank you all for input
 
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