My check engine light has been on for years and years, except for when the battery has been disconnected. Then it comes on during operation in due time. It is the key-code 72, Catalytic Converter Efficiency (or whatever the term is).

Today it stayed off. Code is still stored, I get the 72 when I pull codes with the key switch.

First time I've seen this on mine. Haven't disconnected the battery in a couple of weeks, power did not go out because radio presets are still there.

 

Is that for the recall that I get a notice for every time I enter my vin somewhere? Have you ever taken it to the stealership?

 

I have to admit, posting about the CEL going out is different. I love how you're suspicious though as a result. I ignore mine as it's always O2 reading and Alt circuit. O2 because of my LPG system and I'm not sure on the Alt one, my alt charges fine and was rebuilt by the garage next to us who specialises in it.

 

I plan on toughing this one out.

 

I get it. Just curious if yours has the same recall mine does, supposedly. Although I've replaced my cat.

 

The bulb is burnt out. It happened on my WJ because of a P0740 code. Been on for 6 years. Watch for it on the startup bulb check.

 

Haha! Pretty classic topic.

As Dave stated, look on startup to see if the CEL comes on (or do the key trick to test the cluster).

 

The bulb did not burn out, because that is how I read the codes through the key switch method.

Would like to know why all bulbs are not made out of this stuff, it has been on more often than not since 1996.

 

They reflashed the computer around 2012 or so. That was the last time I took it to the dealer. Was looking for any recall on the driver's seat. Finally replaced the seat on my own last summer.