ningja

TL;DR: I have a 2005 Sport. My CEL has been coming on and going off for several years. My Automatic doesn't detect the CEL, and no mechanic is able to confirm any recorded error code. So what in the world could cause the CEL to come on if there is no error code?

Longer story:

For 5+ years my CEL would come on for a few minutes and then go off. I would just assume it was a glitch or something. And if the light turned off eventually, I wouldn't have much to worry about.

I finally had the dealership to check it out while fixing something else. They claimed something about steering that needed to be replaced. A second opinion by an RX8 mechanic said nothing was wrong with the steering. I had them fix the other problem (coils, engine flood), but the CEL behavior didn't change. I told them about the CEL, but they said no error code was recorded.

I bought an Automatic which is supposed to read the error code. I was hoping that if I had a reader connected while the CEL came on, I would have better luck diagnosing the problem. CEL came on, Automatic said nothing.

So what could cause the CEL to come on but have no recorded error code? I would really like to be able to trust my CEL.

I know that it comes on more often when it's warmer outside (I live in Oklahoma). It used to come on during the summer months. But now it's crept into colder months now too. Now that it's warm outside, the CEL almost always comes on every trip now, especially, but not limited to highway driving.