Back to Forum
Post a Response
    Ford Mondeo 2002 2litre Duratec HE Strange one! Archived Message

    Posted by Derek Warwick on October 6, 2007, 4:01 pm

    Hi all,
    Had an interesting one last week. This car had an engine management light coming on and a code 171 (Fueling system Bank 1 Mixture too lean). This code would clear but return after a few days. Looking at live data the only unusual thing I could see was the downstream oxygen sensor was switching the same as the upstream one. I scoped out both oxygen sensors and sure enough upstream switching nicely, downstream switching almost exactly the same. So I'm thinking Cat u/s and upon measuring temperature of Cat it looks as though nothing's happening. I also check for air leaks and exhaust leaks-none found and scope all the other sensors while I'm at it. Can't find anything else wrong with it so I go ahead and fit a new Cat. Guess what, after a few days, customer rings back to tell me the lights back on again. Anyway, short story long, he's working near a Ford main dealer and books it in for a diagnostic check and when the service guy hears it's had a new Cat he says "well that'll be the fault then!" So I ask the customer to get him to guarantee that a new Cat will cure the fault before he fits another otherwise I won't be able to send it back to my suppliers. He rings me back later the next day and the main dealer declares the Cat fine but says the injectors had to be calibrated? Now I've heard about diesel injectors and calibration, but petrol injectors needing calibrating? Is this just dealer speak for a flash upgrade of the software or am I missing something. Could someone please enlighten me.
    Many thanks,
    Derek
    P.S.
    Sorry for the long post.

    Message Thread:


Copyright © uk autotalk