"Check Engine" Light ON/OFF

[arks]

'98 GC LTD 5.9. Light came on and stayed on 2 days in a row but it ran just fine. Hasn't come on since and I'd hate to waste a trip to the shop if there's nothing really wrong. Now the wife's afraid to drive it.....
What would trigger the "Check Engine" light for just a short time like this?

[MrKill]

Probably just your gas cap. If its not done up tightly, the Check Engine light will show, then it will reset itself when the cap is tightened. I found out the hard way...

[arks]

Thanks. That's most likely what happened since it has been running A-OK. The better half seems satisfied with that answer, too!

[mcs219]

Just had that same problem with my 98 5.9. Light stayed on for about 2 days, then off for 2, then on, etc. However, mine also had a rough idle. The mechanic plugged his computer in (for $50) and saw that the #8 cylinder was occasionally not firing. Installed new spark plugs (another $50) and so far no problems.

[mdavis123]

Mr. Kill,
Do you think the gas cap thing would hold true for a 4.0 as well? I have
been thinking the difference was between regular, and premium gas.

[dksob81]

ok for sure quick answer goto AUTOZONE and have them hook the scan tool up and scan the computer for the code. it's free and only takes like 10 seconds. seeing that u ahve a 98 they can scan it. I wish I had that option when my check engine lite comes on (94 Grand Cherokee 5.2L), but I have to do the old key trick, or pay $30 at the dealer forget that.