Rear o2 sensor voltage high?

[GoDuke4382]

I'm looking at my friend's 1999 TL 3.2, and he is getting a code for converter efficiency threshold failure. When I view the o2 voltages with a scan tool, the front 02 looks normal.. starts out around .450-.500 volts, and becomes more active as it warms up. The rear sensor starts out at 1.25 volts, and takes quite a while to warm up and start switching. I used to work as a tech, but I've been out of it for about 10 years.. from what I remember though, that rear reading should not be that high. I would expect it to be similar to the front, about .450-.500 until it warms up. The kicker is.. it is a new 02 sensor, only a week or so old. I don't know if he got an Acura sensor, or aftermarket.
The converter is also new.. not Acura, but a Midas model.
There is another code stored in the PCM.. P1676, which is the ABS/TCS circuit losing connection to the PCM. I have not investigated that yet, but I didn't think the two were related, or shared any circuits. (Haven't verified this yet).

Am I correct in thinking that the initial voltage of the rear 02 is too high at 1.25? Thanks in advance for your help..

Rob Roberts

[hondacuraworld]

As far as the P1676, A bad ignition switch (the electrical half) could be the culprit.

Inspect the ignition switch solder joints for any signs of overheating. If you notice the solder joints are melted, replace the ignition switch. Check for poor connections or loose wires at the ABS/TCS control unit and the PCM if this is not the case.

As far as your O2 sensor, anything above .8v is fine. The ECU is watching for a swing greater than .5 volts from the initial cold reading.

I'm thinking the converter is the issue. We've seen many times where an aftermarket converter doesn't contain enough guts to pull the nasty stuff from the exhaust system