Guys, let's not automatically link the CEL with a safe mode. A failed gas cap or removal of rear O2 sensors will trigger the light, but not behave differently. A failed TPS or MAP sensor may also trigger a CEL, but the resulting driveability is the ECU trying to manage to run the engine anyway, not that the yellow light condition forced it into a limp-in mode. The light comes on for lots of reasons, but the commands to change the fuel strategy is to keep it running.