First post here.... My wife and I are currently vacationing in Moab, UT. However, when we came over the Eisenhower tunnel in Colorado (elevation around 11,000ft), the light for the emission system came on and has since stayed on for two days now. The car still seems to run just fine; but we're concerned about it. Have any of you had any emission system problems due to high altitude before?

 

You Accord should have figured it out, but 11,000 feet is a out of the normal range. I would not be concerned unless a red light comes on. What I would do is find an Autozone, O'Reily's or similar store and have them pull the code and reset it. Or disconnect the battery for a minute and reset the code that way. You may not have the light come back on again. Let us know the code if you find out what it is.

 

Thanks for the quick reply! There's a Napa right next to our hotel. I'll stop by first thing in the morning and let you know how it goes.

 

Post the actual code on here (like P1234) and not just the description.

 

Turned out to be P157 & P158. Bad O2 sensor. Ran it into a repair shop here in town. They said it was the O2 sensor after the catalytic converter and wasn't an urgent thing to get fixed right away and we should be fine driving it back home to MN.