GM Truck Club
THE PREMIER CHEVY TRUCK & SUV FORUM
Founded in 2004 ~ We're the #1 Chevy Truck & SUV Forum.
Silverado & Sierra | Tahoe & Yukon | Suburban & Yukon XL | SUV & CROSSOVER
Results 1 to 8 of 8
  1. #1

    Default HELP with diagnostic codes

    I've been experiencing a bit of rough idle since I've owned my 05 Tahoe (01/12) and then it seems to smooth out. Until this week, and now it stays very rough at idle almost like it's ready to stall and the check engine light came on today.


    Got 3 codes...


    P0300 - Multiple misfire detected
    P0174 - Bank 2 System too lean
    P0151 - O2 sensor low voltage Bank2 Sensor1


    Do you think this is as simple as the O2 sensor or is that getting thrown because of a different issue?


    Thanks,


    Vince
    Last edited by vinceseg; 06-02-2012 at 12:36 PM.

  2. #2

    Default

    Quote Originally Posted by vinceseg View Post
    I've been experiencing a bit of rough idle since I've owned my 05 Tahoe (01/12) and then it seems to smooth out. Until this week, and now it stays very rough at idle almost like it's ready to stall and the check engine light came on today.


    Got 3 codes...


    P0300 - Multiple misfire detected
    P0174 - Bank 2 System too lean
    P0151 - O2 sensor low voltage Bank2 Sensory


    Do you think this is as simple as the O2 sensor or is that getting thrown because of a different issue?


    Thanks,


    Vince
    Vince.....here is information, regarding each of the Trouble Codes you've posted above, hopefully the infor. will be able to give you some help with each Code,

    A Code P0300..........Basically this means that the the car's computer has detected that not all of the engine's cylinders are firing properly.
    A P0300 code indicates a random or Multiple Misfire. If the last digit is a number other than zero, it corresponds to the cylinder number that is misfiring. A P0302 code, for example, would tell you cylinder number two is misfiring. Unfortunately, a P0300 doesn't tell you specifically which cylinder(s) is/are mis-firing, nor why,

    .....Code P0300.....may mean that one or more of the following has happened:

    • Faulty spark plugs or wires
    • Faulty coil (pack)
    • Faulty oxygen sensor(s)
    • Faulty fuel injector(s)
    • Burned exhaust valve
    • Faulty catalytic converter(s)
    • Stuck/blocked EGR valve / passages
    • Faulty camshaft position sensor
    • Defective computer



    A Code P0174....Basically this means that an oxygen sensor in bank 2 detected a lean condition (too much oxygen in the exhaust). On V6/V8/V10 engines, Bank 2 is generally the side of the engine that doesn't have cylinder #1.

    .........P0174.....may mean that one or more of the following has happened:
    • The MAF (Mass Air Flow) Sensor is dirty or faulty. Note: The use of "oiled" air filters can cause the MAF to become dirty if the filter is over-oiled. There is also an issue with some vehicles where the MAF sensors leak the silicone potting material used to protect the circuitry.
    • There could be a vacuum leak downstream of the MAF sensor.


    .....A Code P0151.....refers to the first oxygen sensor on Bank 2 . P0151 means the O2 oxygen sensor's voltage remained low for longer than 2 minutes. This, is interpreted by the ECM as a low voltage condition and sets the MIL. Bank 2 Sensor 1 is located in front of the catalytic converter

    Code P0151.....may mean that one or more of the following has happened:

    • Faulty O2 oxygen sensor
    • Short to voltage on O2 signal circuit
    • High resistance or open on O2 signal circuit

    MIKE


    99"SILVERADO
    5.3 l 3.73 l G80
    BLACK BEAR CUSTOM TUNE
    SNUGTOP l COLORMATCH l KATZKIN










  3. #3

    Default

    TYVM Mike. Wow it doesn't exactly narrow it down huh? I have a mechanic friend that seems to think it can be a leaking intake manifold gasket which says is common on the 5.3 and could cause the lean condition. I'm going to have him look at it, not the stealership they've been getting way too much of my money lately. I just hope it isn't the catalytic.

  4. #4

    Default

    Quote Originally Posted by vinceseg View Post
    TYVM Mike. Wow it doesn't exactly narrow it down huh? I have a mechanic friend that seems to think it can be a leaking intake manifold gasket which says is common on the 5.3 and could cause the lean condition. I'm going to have him look at it, not the stealership they've been getting way too much of my money lately. I just hope it isn't the catalytic.
    I would look at finding/locating the Random Misfire First, and then check the 02 Sensor on Bank 2 Sensor 1, which the 02 Sensor Located on the Passenger side of the Engine, in Front of the Catalytic Converter.

  5. #5

    Default

    Quote Originally Posted by 99'HEARTBEAT View Post
    I would look at finding/locating the Random Misfire First, and then check the 02 Sensor on Bank 2 Sensor 1, which the 02 Sensor Located on the Passenger side of the Engine, in Front of the Catalytic Converter.
    Probably a stupid question but how do you check an O2 sensor? Do you bypass it somehow and see if it corrects the rough idle?

    I also assume I shouldn't really be driving it in this condition? Is 20 miles or so to get to my guy to diagnose it ok? Thanks.
    Last edited by vinceseg; 06-02-2012 at 04:48 PM.

  6. #6

  7. #7
    Sr. Engineer
    Join Date
    Oct 2010
    Location
    Indianapolis, In
    Posts
    493

    Default

    All that from an O2-sensor? Thanks for posting back with the resolution.
    2000 GMC YUKON SLT, 5.3L tow pkg, G80 rear/w 3.73 gear

  8. #8

    Default

    Quote Originally Posted by dpeter View Post
    All that from an O2-sensor? Thanks for posting back with the resolution.
    Mechanic says it would normally also throw P0171 if it was the intake, which is too lean on the drivers side. I managed to get both replaced. ;)

Similar Threads

  1. Diagnostic Trouble Codes
    By TrailLeadr in forum Chevy Truck Tech Forum
    Replies: 5
    Last: 07-20-2012, 06:02 PM
  2. Diagnostic Trouble Codes
    By TrailLeadr in forum Chevy SUV & Crossover Tech Forum
    Replies: 1
    Last: 01-20-2011, 11:26 PM
  3. GM OBD2 Diagnostic Trouble Codes
    By TrailLeadr in forum GM Powertrain
    Replies: 22
    Last: 01-04-2011, 12:08 AM
  4. Diagnostic Trouble Codes
    By TrailLeadr in forum Chevy Suburban Forum (GMC Yukon XL)
    Replies: 0
    Last: 03-15-2007, 09:44 PM
  5. Diagnostic Trouble Codes
    By TrailLeadr in forum Chevy Silverado Forum (GMC Sierra)
    Replies: 0
    Last: 03-15-2007, 09:44 PM

Tags for this Thread

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •