Lilredsx

I’ve had my 240, a 95 with an auto box, for almost a year and the check engine light has always been on. As money permitted I’ve replaced or repaired things that were messed up on the car. I also took the car to Advance to get a scan to see if I could figure out the reason for the light. The codes pointed to the transmission, and indeed the TPS was bad and the tranny would slam into gear. Changing the TPS fixed the hard shifting but the light stayed on.

Recently I had to take out the exhaust behind the cat, to change out my subframe bushings. In my rush to put everything back together I messed up the stud on the cat so there was an exhaust leak. This Friday I tried to take out the cat to fix the stud and ended up breaking a bolt from the cat to the downpipe. Since time didn't permit I had to drive to work with an open exhaust until I can either get the bolt taken out and the stud fixed or a test pipe or new cat.

On the highway to work, I happened to notice that my check engine light is no longer on. I figured that the bulb must have burned out. When I got a chance, once I was stopped, I turned the car off and then on. All the warning lights lit up, including the check engine light, and then all went out as normal.

So, why would my taking off the cat cause my check engine light to suddenly go out? And funny thing about the cat is that it was straight through. No baffles or anything, is this normal for the 240s?