A couple weeks before it was due for a NYS inspection, the battery shorted out and needed replacement.
Since then, and after approx 2000 miles, the Catalyst and O2 OBD-II status is still not ready.
Here's some details.
The engine running temp is over 180 F (on the road using an ODB scanner I see it range between 182 and 196). I looked for a replacement thermostat, and it was rated at 180. So the temp range appears to be normal, correct?
There has never been any Active DTC's, however a "pending" Knock Sensor shows up.
I ran an HO2S and Catalyst Drive Cycle several times.
IE: Idle till op temp achieved. Drive at 56MPH for 3~5 minutes. Decel for 10 seconds. Back to 56 MPH for 3~5 minutes. Decel to stop (keep running) Check readyness; Still not ready.
Looking at some other specs, the pre cat O2 has normal voltage and fluctuation.
The post cat reads 3 volts constantly, and I never saw any fluctuation while driving. BTW out of arguments sake I replaced the secondary 02, but realized after, it was not neccessary. The readings were the same with the original and new sensor.
This car recently drove some 1,400 miles -mostly highway. The Cat and O2 are still "not ready".
My bad, I forgot the decimal point. It is 0.30 volts (-0.5%).
I thought the max voltage an O2 sensor can create would be about 1.0 volt. If there was a + feeding short, then maybe it would read 5~12ish volts? Also I'd get a DTC then, yes?
Since there is no voltage fluctuation, it made me think maybe the heater part of the sensor isnt working right. But I thought that should push a DTC. Wouldn't it?
I'm going to try and disconnect the down-stream O2, and see if that gives me a code. Also I'm thinking I can ohm out/check continuity between the O2 sensor connector and the ECM. The reason I have hessitated to do any of this is due to the lack of trouble codes.
have the same problem?
Sunday, August 8th, 2010 AT 5:58 PM