Engine warning light

  1. #1
    Right driving Home on the motorway and the engine warning light pops up

    No noise, no difference in driving or anything
    Recently the second lamda sensor popped out (rusted) and no warning light
    Bro used his diagognostic plug thing and said lamda sensor b so was the one after the cat that had recently popped out
    I'd got a new cat and plugged the old sensor in
    He cleared the fault and the light isnt back on but when I pulled on my drive the engine revved from idle to 1100/ 1200 revs up and down for 20 seconds with no feet on the pedals

    Fuck knows
    Aint too worried coz it hasn't happened again but if it's an easy fix I'll do it

    Problem is the lamda sensor obv but is it fucked? Why did the light just come on... After passing the mot

    Cheers guys!
  2. #2
    had this happen to me. just randomly popped on one day.

    the second lambda is supposed to read clean air. usually unplugging them stops the problem but flags to EML (maybe??) as i had a 1.1 with a knackered lambda (hesitating and surging!) and i just left it unplugged for a few weeks!