P0135 & P0143 Bank 1 Sensor 3?

[striker1211]

I got a check engine light yesterday and pulled these two codes. I suspect that the wire for one of the sensors is melted because I have smelt burning plastic (almost like burning electrical tape) recently. My question is, could I have a bad PCM also? The P0135 code makes sense (Bank 1 Sensor 1). The P0143 does not make sense because "Bank 1 Sensor 3" does not exist... does anyone have any idea why it would be saying this? Thanks.

[JohnO]

Apparently Toyota uses "sensor 3" to refer to the rear O2 sensor on some cars. See this:

http://engine-codes.com/p0143_toyota.html" onclick="window.open(this.href);return false;