Can dampness cause check engine light to come on?

MS2SCSI

MEMBER
HONDA CIVIC

1997 Honda Civic LX, 146,000 miles - set in the driveway for 4 days during downpours. Started a little rough on day 5, and got better after 5-10 min of driving. However, check engine light came on after the first 3 min. (Just had an oil change a week prior to this).
Same thing happened last year under similar circumstances. Replaced spark plugs and did a full tune up then.
Is there something that I need to worry about? Inspection time is coming up - is there something that needs to be looked at?
Thank you!

1 Reply

CARBOY

MEMBER
14 POSTS

If one or more spark plug wire insulation is bad, the moisture in the air could condense on the wires and could make the voltage run along the outside of the wire and never make the trip to the plug gap. This would cause a misfire which would be picked up by the ECU pronto since it is a potentially damaging situation for the catalytic convertor. Pull the codes. A general misfire code is PO300, cylinder specific misfire codes are like P0302 for cyl. #2, 303 for cyl #3, etc. The distributor cap could have microscopic cracks in it to trap and hold moisture too. Engine heat will eventually dry this out and the motor will in many cases quit running rough. I don't have inspections where I live but I suspect that glowing check engine light won't go over too well or the codes trapped in the history file.