I have a 1998 Grand Cherokee 4.0 Ltd. LPG converted,which runs beautifully, except for one minor issue.
Whenever I go on the motorway after approx. 6-8 miles the "check engine" light comes on but with no effect on performance or anything else. I have done the trick with the key and no codes show.
I re-set the indicator by removing the + lead on the battery with no further indication until the next time I go on the motorway.
This is just an irksome minor problem but it gets on my tits that I can do 200 miles commuting and pottering around with no problems but after 10mins on the motorway, this damned light comes on.
Any ideas anyone?