Back to Forum
Post a Response
    Chrysler Neon 2007 2.0i High CO% at fast idle Archived Message

    Posted by Paul Foster on April 10, 2008, 4:28 pm

    Hi Guys.
    Having a bit of a laugh with this one!
    Customer reports very high fuel consumption and 'check engine' light on.
    Emissions all over the place and DTC (I forget the code. Sorry!) suggests O2 sensor fault. Checked the sensor on live data and with scope which reveals the sensor signal freezes when the sensor gets hot (at around 0.5v). When snapping the throttle open the signal does not budge. Right then - new sensor ordered from the dealers and fitted today. signal now switching normally at idle with emissions spot on. When RPM raised to 2500 the co shoots up to 6 - 8%.
    Live data shows manifold pressure at 34kpa - Mityvac shows vac is closer to -75kpa (at idle and 2500rpm). Testing at the sensor shows the usual 5v feed, 0v earth, signal wire, etc and the signal votage varies with engine load.
    I suspect the Map sensor is faulty but at £141.12 from the dealers it will be an expensive mistake if I am wrong.
    Does anybody have any thoughts on this or know where I am likely to find a sensor (even a second hand one!) for a more reasonable price?
    Thanks for reading this long, boring post.
    Cheers - Paul.

    Message Thread:


Copyright © uk autotalk