P0172 code - Chevy Suburban & all GM Trucks

Discussion in 'Chevy Suburban Forum (GMC Yukon XL)' started by Alan Crosby, Aug 15, 2011.

  1. Alan Crosby

    Alan Crosby Member

    The CEL came on the other day while my wife was driving the vehicle (I can't decide - do I call it a truck, car, vehicle? :money:). The Stabilitrac light came on briefly and then the Check Engine Light came on shortly after. I went up to Advance Auto and read the code and it posted a P0172. Reading the code turned off the light.

    A quick scan of this forum yielded a few hits about MAFs and oiled filters, which the original owner installed. I hadn't looked at it since buying the vehicle, so I went ahead and cleaned the filter. While I was at it I took off the MAF and sprayed it with carb cleaner. After everything dried out I reassembled everything. The next day the same symptoms came back.

    So I was thinking that the MAF must be the culprit and I started looking for a place to buy one online this morning. I came across another post mentioning a TSB for this code (#03-06-04-030F) and it was referencing clogged fuel injectors. That reminded me that I had just run a bottle of Techron Fuel Injector cleaner on the last tank of gas. I wonder if one of the injectors is now squirting more fuel then before and is causing this rich condition?

    Any thoughts?

    PS - Are there any online sources for GM parts that show pictures and part numbers? The ones I've found so far including the one affiliated with this site don't offer either.

    ---------- Post added at 10:19 AM ---------- Previous post was at 10:06 AM ----------

    I forgot to mention that it idles a bit rough when started, but I have not noticed any drivability issues, before the light came on or after I my initial attempts to fix it.

    99'HEARTBEAT MODERATOR Staff Member 5+ Years ROTM Winner 1000 Posts Platinum Contributor

    When Cleaning a MAF Sensor......Never use Carb Cleaner, when Cleaning a MAF Sensor.....Use CRC's MAF Sensor Cleaner Only.

  3. mfleetwood

    mfleetwood Epic Member 5+ Years ROTM Winner 5000 Posts

    X2 on the MAF cleaner.....

    Nice pic of the can Mike!! Very thorough as always!!
  4. Alan Crosby

    Alan Crosby Member

    Okay, I'll pick up a can and try it.

    Is there anything special I need to do have the computer relearn afterwards or is just reading the code to get the light to go off enough?
  5. mfleetwood

    mfleetwood Epic Member 5+ Years ROTM Winner 5000 Posts

    I do a lot of off-roading and things can get pretty dusty, thus I get the code frequently. Sometimes the code resets itself after I let the truck sit and/or after I clean, but for the most part, I just reset myself with my programmer. Sorry not an exact answer, but I hope it helps some.
  6. janikphoto

    janikphoto Rockstar 3 Years 100 Posts

    If you reset things by disconnecting the battery for an hour or more, be sure to let the truck sit at idle for about 5 or 10 minutes when you first start it again. I've found this is the best way for the computer to "re-learn" things on every vehicle I've owned. When I just start it up and drive, it idles much worse and tends to hesitate some for the next several days. Especially for vehicles with any sort of mods on it.
  7. Alan Crosby

    Alan Crosby Member

    Well I got into BB (Big Bertha) and headed out to Advance for a can of CRC MAF and to borrow their Code Reader, and lo and behold the CEL went off. I went ahead and got the can of MAF cleaner anyway for next time.
  8. silveradotrailblazer

    silveradotrailblazer Epic Member 5+ Years ROTM Winner 5000 Posts

    I would clean the MAF with the CRC MAF cleaner just in case the carb cleaner left some residew on the MAF hot wire. This residew could cause the MAF to send false signals to the trucks computer.

    99'HEARTBEAT MODERATOR Staff Member 5+ Years ROTM Winner 1000 Posts Platinum Contributor

    I Agree with STB....100% on cleaning the MAF Sensor with the CRC Cleaner, now rather then later.

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