Check engine light JDM

Discussion in 'Subaru' started by SurreyGTB, Sep 13, 2016.

  1. SurreyGTB

    SurreyGTB New Member

    Joined:
    Sep 13, 2016
    Messages:
    1
    Location:
    Slurrey, BC
    JDM 1999 Subaru Legacy GTB twin turbo

    Check engine light comes on as soon as the engine has fully warmed up and as soon as I release throttle. It sometimes stays on for a real short time or for a few minutes. When light is on, engine has poor acceleration....sometimes, I found I could get the light out by using at least 3/4 throttle. Light may come on a few times on my 45 minute commute or just once. Any ideas?

    Thanks
     
  2. magnavahn

    magnavahn Vahn

    Joined:
    Jun 22, 2013
    Messages:
    350
    Location:
    Central Alberta
    First, pull any stored engine codes. With my 97 Subarus, the code would be stored even after the light went out. I'm not as familiar with the legacy's but they may be a similar OBD-I style. Link:
    http://legacycentral.org/library/literature/codes.htm

    I'm going to guess it is related with idling airflow: perhaps MAF or IACV. Early generation subaru's were plagued with a faulty idle air control valve (iacv). Though this was much improved by the version 3 imprezas. Good luck.
     
  3. mconor7

    mconor7 New Member

    Joined:
    Jan 12, 2017
    Messages:
    22
    I think the knock sensor or MAF are failing. This is a common issue on twin turbos.