vectra b warning light

hi there ive got a vectra b 2002 2.2 sri150.couple of days ago on way back
from holiday,after doing 400 miles and getting average 35mpg ,I fuelled up
at a asda,and from the moment I continued my journey the mpg dropped to
about 25mpg and this was on the motorway at a steady 70mpg.A day later set
off for a run and a warning light came on.looked it up in manual and its the
exhaust ,immobiliser, electronic ignition light.I then refuelled again with
non asda fuel and im managing to get my mpg back to normal but the warning
light is still on .any ideas anyone
russ

 

Hi Russ
Had this problem awhile agoand discovered that when i went to Asda the
petrol has water in it. Ended up having to get a diagnostic check done and
reset the system again. Hence I never ever use asda again.

~regards

 

Thanks dereck that's what I was thinking because it happened so quickly
after fuelling up with asda petrol,got it booked in and prepared for the
diagnostics rip-off
russ

 

Might also be worth waiting till you have got lower on the fuel and run some
redex through the system, and possibly change the fuel filter.

dereck