Truck is running normal
Service Engine Soon light came on, took to a "Autozone" Got error code
P0420
"Catalyst Efficiency Below Threshold"
Bank 1.
Replaced up-stream (engine manifold) Oxygen Sensor With Universal fit 3 wire, 1 white 2 black O2 sensor. Reused original plug from old O2 sensor, making sure to rewire it the same as to original.
Took back to Autozone, cleared error code. Ran truck at highway speed for about a 1/2 hour, Service Engine Soon light came back on.
Now what? HELP!
I'm trying to avoid taking it in to be serviced, if I can. Don't have the $$.
Thank you for any help!
Saturday, June 1st, 2019 AT 7:10 PM
(Merged)