The post cat o2 is giving the code. I put an after market cat on 3 yrs ago because the oe one was plugged up. Back ground; car was at a shop and the customer was just throwing money at it. New tires, mas airflow meter. all new ac componets and the cat became plugged, so I bought the car cheap.Cat was plugged so bad it would only idle. Melted the pre cat o2. My issue was why did the cat get plugged in the first place. The car had a recall on this problem but i was over the mileage point for dealer to fix.On my little scan tool the new pre cat o2 was reading rich around .8volts at idle and the car would load up with carbon running around town. I would blow it out by getting on the freeway and see black smoke pour out for a few seconds and clear out. So new mas airflow meter, new air filter,new oe spark plugs,new cat. My question was there a ecm update with the recall? and also post cat o2 keeps tripping code. I seen on youtube a resistor and a capacitor can be wired in to o2 harness to tone down the post cat o2 signal. Has anyone tried that?

Cars & Trucks - AC