any thoughts on p0141 and p0142 codes? 97 blazer w engine. running good, but my son (18) says it misses occassionaly when wet or raining. I have yet to duplicate the miss. today when dry the check engine light appeared.before he drove it today I changed the supentine belt, and wiggled a few electical connectors ie the coil and several sensors above the intake manifold and all of the spark plug wires. at the cap and the plugs. it has never set a check engine light before today. i cleared the codes and we see if it comes on .

 

P0141 is heated oxygen sensor performance, sensor 2, I don't see a code P0142 fo r '97, I do see a P0143 which is cicuit voltage low to O2 sensor 3.
You may have an old , contaminated or slow oxygen sensor.

 

P0141 - O2 Sensor Heater Circuit (Bank 1 Sensor 2) --> this is the precat sensor directly ahead of the catalytic converter
P0142 - O2 Sensor Circuit Malfunction (Bank 1 Sensor 3) --> this is the post cat sensor directly after the catalytic converter

I'd inspect the wiring for these sensors to make sure that nothing has pinched them possibly causing a short or weak connection. It is odd for both of these sensors to go bad. They are ONLY for catalyst monitoring and have no impact on fuel delivery for the engine.