Bike Running Lean throwing code P131 P151

Discussion in 'Softail Models' started by Delilah2007, Jun 5, 2014.

  1. Delilah2007

    Delilah2007 New Member

    For the past couple months my bike has just been running not like its self. During start up it coughs and nearly dies until completely warm. I have to give throttle just to keep it running or it will die out when it coughs. I took it to my local dealership and they found i was missing a clamp on my fuel line. The nice guys where i am at replaced my whole fuel line added the clamp and changed my fuel filter. Problem was still there. So I then took it to a shop near me to do the 10,000 mile service. Got it back and was still coughing. Winter hit put it up for a month or two. Heard about seafoam and put 5 oz in when i filled up and bike is running better but still coughing. Though my rear spark plug was stripped but took it to the HD shop again yesterday and they said it wasn't and the looked at my download and i have the stage 1 map on since i have an aftermarket exhaust that i dont know what it is got it that way and stage 1 air cleaner. So right now i am at a stand still. I've spent enough money i kinda wanna fix this without taking it to the dealer. Also the guy who had the bike before me for some reason had the 10r12 spark plugs in it. But i put back stock. I am new here and would really appreciate some help. Thanks!
  2. mouthful

    mouthful Active Member

    Coughing and chocking, Check for an air leak at the intake manifold.
  3. Bodeen

    Bodeen Well-Known Member Staff Member Moderator Contributor

    Does it run good at any RPM?
  4. Jack Klarich

    Jack Klarich Expert Member

    Read this
    This is the exerp from the 2008 Harley Dyna Service Manual that talks about the 131/151 codes.

    You will note that they tell you to "clear and ignore" the codes. Their reference is primarily associated with break-in, but it seems strange that something that is acceptable at 999 miles because an issue at 1001 miles.

    Please notice HD's list of causes for 131/151 codes.
    Poor Connections
    Dirty Injectors
    Loose O2 Sensor
    Loose/Leaking exhaust
    Engine misfire

    We see the last three causes as primary candidates to trigger the codes, especially with the IED's in place.

    We also have evidence from a state run EPA test laboratory that codes are very likely to be triggered just after initial startup, between the time the engine starts and it revert to normal closed loop operation.
  5. Delilah2007

    Delilah2007 New Member

    How would you recommend checking for a leak.. i had the filter off put my finger over the hole near the top before the opening and it shut off. i read that means there isnt a leak. but idk. the bike runs good at high rpms. If i give it a steady low throttle it pops coughs and dies. And yesterday I took it to our yearly bike show left it out with all the other bike. over 100 degrees and when i started it it coughed the whole time. if i wasnt on the gas it would almost die out and when i took off well lets just say i was super embarrassed i was having to pull in the cluth gas it hard let it out just to keep moving. And the backfiring was awful.
    Last edited by a moderator: Jun 9, 2014
  6. stray dog

    stray dog Junior Member

    use a propane torch (unlit) around intake. any rpm change and u found your leak