Cadillac CTS First Generation Forum - 2003 - 2007 Discussion, Questions about O2 sensor codes P0160 & P0161 in Cadillac CTS Coupe, Sport Sedan and Sport Wagon Forums; I have a 2003 CTS 3.2 thats showing codes - P0160 - O2 sensor circuit no activity (bank 2 sensor ...
I have a 2003 CTS 3.2 thats showing codes - P0160 - O2 sensor circuit no activity (bank 2 sensor 2) and - P0161 - O2 sensor heater circuit malfunction (bank 2 sensor 2).
After a lot of searching, I'm noticing multiple threads where people with the same 2 codes will change out the drivers side post-cat sensor (or even all 4 at times) and still have the same codes. The problem is that none of the OPs post up a solution in any of the threads.
A few posts had mentions of checking the wiring, which was my first thought when I ran the codes. I went under the car to check all of the connections and I found a good amount of oil dripping from around the O2 connectors (rear main seal?) All of the visible wiring seemed to be OK. I unplugged the drivers side sensor and there was some oil in the connector itself that I cleaned out. While I had it unplugged, I started the car and let it run for a few minutes and pulled the codes again to be sure that the drives side was the affected circuit. I got the same 2 codes, plus one additional pertaining to bank 2 sensor 2.
So now what? My next thought would be to test the wiring from the O2 sensor to the ECM. I own a decent voltmeter, but I have no idea how to use it.
Maybe someone out there has solved this problem or has seen it before and can offer me some sort of direction. The car is due for inspection on Monday and will fail emissions with these codes present.
you can shoot the wires from the O2 sensors to the ECM and know whether or not you are getting what you are suppose to. mine was showing proper voltage all the way to the ECM. had an extra ECM sitting around, popped that in and everything went away. went ahead and flashed that extra ECM to my VIN and i have never had it happen again
Thanks for all of your advice. I'm going to go ahead and replace the ECM and the crank sensor. The car has been exhibiting some other problems like showing no gas when there is a full tank and the keyless only works about 50% of the time recently.
BTW I just noticed that you offer .pdf service manuals. I'm going to shoot you a PM with my email. I can really use one right now.
ECM replacement fixed my P0160 and P0161 codes on my '03. I'll update original thread. Software includes updates to idle and shifting issues.
Your oil is very likely coming from valve covers, they are attached with low torque (aluminum you know) and the screws tend to get loose. Tightening them down might help.
Factory installed gaskets have sealant applied on the cover body where the cover molds around the shaft, that should tell you about the engineering. I replaced my gaskets and haven't had a leak since then in over 30k miles.