fnel1771

I have a 08 CS with 23k miles that has a recurring problem of throwing code P02196 (pre cat sensor stuck in rich position). Last year the dealer diagnosed the CAT as faullty and replaced it under warranty. The issue remained and they reflashed the car. The problem persisted, after which they washed their hands, since they claimed that the installed Remus exhaust was to blame.



This spring I also upgraded to the GT3 throttle body and plenum as well as changing the faulty sensor. The code still comes up! Any ideas as to what the issue and what the problems/fixes are?



All input much appreciated



Frank

Macster

Well, based on what you posted I'd say the indicated O2 sensor is bad.

There can be electrical checks/tests to confirm this. I do not have my diagnostics reference handy to list them.

Kind of risky -- the more a working O2 sensor handled the more likely it gets compromised -- but you can consider swapping sensors side to side to see if the error code follows the sensor.

A risk is the sensor connector is bad and it can damage the wiring harness connector on the other side. You can mitigate this risk somewhat by carefully examining the connector pins and sockets of the suspected sensor and its harness connector for any signs of corrosion or physical damage.

Handle sensors with care. Do not touch the tip. Do not "clean" the sensor. Do not use any thread lube.