code checking

Has anyone come across this error on their 4Runner? It's throwing this code out of nowhere, and I have a great warranty. Toyota is saying this isn't exactly pinpointing an exact cause to justify to the warranty company to replace "x." This is highly frustrating. This all started a few months...

Hello all. Embarrassing post. 1994 80 series with OBD1. The little 2 prong jumper you have to pull out before checking codes… Yeah. I lost it. Not sure what to do. I have been driving it like this for some time without realizing I lost it and never put it back in. Can anyone advise...