I just had the MAP sensor replaced and a coolant leak fixed at a shop. a day later i got the SES light and P0420 (catalytic converter) code. I reset it and it came back on a couple of days later. My question is: should a catalytic converter fail after only 49K miles? Also, is there anything the the shop could have unplugged or pinched an 02 sensor wire or anything else while doing their service? Strange that this is the first time this error came up. Tomorrow I will get the car warmed up and get the temp of the front of the cat and rear of the cat and see if it is bad. That's how we used to check them. Hotter in rear of the cat normal, hotter in the front clogged. BTW, no loss of power. Thanks for everyone's help.
Mark
Mark