On my 2004 Deville the engine check light occasionally comes on. The fault code coming up is PO741 something about a torque converter solenoid problem which is either stuck or off. What do I do to fix this fault or do I need to worry about it.
Many members go for years without fixing this because it is expensive (~$1,500 at a good indie shop, ~$2,500 at a dealer) because the transmission has to come out. Only penalty for not fixing is slightly reduced highway mileage, maybe 1 mpg. But if you have to pass emission tests where you live, you'll have to get it fixed, as it is considered an emissions failure.
You say it only comes on occasionally. It will probably get worse with time. Also the test for it only runs when you go over 41 mph.