Yesterday, my Check Engine Light lit up in my 2010 RX450h with 9k miles. I tightened the gas cap and I am giving it a couple of days to clear. I had a recurring problem with the Check Engine Light in my old 1999 RX.

Has anyone else had this problem?

 

Probably a vacuum leak somewhere but hey, it's under warranty and you get a loaner. If it were mine I'd take it in. The light is a clear warning of something

 

Based on previous experience with the check engine light in other automobile makes, it usually indicated something amiss with emissions.

 

Update - the light went out today. It must have been the gas cap.

 

Whew, that's a relief. Keep us posted.

 

Well my check engine light came back on. I took it to Auto Zone and the code is P1423 - Fuel tank pressure leak. One of the possible causes is "loose gas cap". However, I am positive the gas cap has been tight. I made an appt with the dealer for tomorrow.

 

may be a defective gas cap. take it in and dealer can do pressure check and visual inspection of the seal.

 

Update - it was my charcoal canister. Dealer won't have the part until tomorrow to install. I have a loaner so no problem.

 

Thanks for letting us know. I recently went through the same thing, only on my 1999 Honda Accord (used to belong to my son). It cost a pretty penny to get the whole thing fixed (vacuum leak, etc.).

Glad to see the light decided to "mis-behave" while you were under warranty.

 

unusual for canister to fail this early in service life. excessive overfilling can cause premature failure of canister so hope this replacement will last as long as the vehicle.

 

I started this thread last August and today the check engine light came on again. I tightened the gas cap and I will give it a few days to see if it goes off. Last time it did go off and then came back on again. Eventually they replaced the charcoal canister. I hope this isn't a yearly event.

 

Ocassionally I round it off to the nearest dollar but never near the top of the neck. It has never been overfilled.

Last time the canister had a leak so I don't see how overfilling can cause that.

 

Update - I took my RX to the dealer and it was fault code P1423 - Fuel Tank Gross Leak. They said it needed a new fuel cap which had to be ordered.

 

Looks like the exact same code as last time. You have to wonder if they're just throwing parts at it.

 

Just replaced the o2 sensor in December on my 2000 - 300 rx, now the check engine light is coming on after rainy weather when the temperature is above freezing, goes off after a day or so when the temp is colder.I bought the car in 2009 & have replaced two O 2 sensors so far very expensive and frustrating!