P0141 & P1456
 

Is it possible that having the gas cap loose (P1456) triggered the O2 sensor (P0141)? Or am I unluckey enough to have a real sensor problem & something more than just a loose gas cap?

The O2 sensor is part of the exhaust and should not have any correlation to gas cap. I'm not familiar with the RL but on Legends they only get set by either the O2 heater problems or the actual sensor. How many miles do you have on the RL? O2 sensors usually last 150-200k unless they get corrupted by something they don't like such as coolant, silicone, or leaded gas.

80,000 miles. That's why I thought it was odd. I was planning on running the car for couple hundred miles to see if the light went away. I've read lots of other strings about removing the negative cable on the battery to reset the Pcodes. Anything I should know before I do that, or do I just turn the car off, undo the cable, wait, and put it back on?

Thanks for your reply.

Since the RL is an ODBII, you should be able to go to Autozone and they should be able to reset the computer for you for free.