So the check engine light came on, so I used my Actron Scanner and found the car is throwing a P0420 code...

From the site:
"Code P0420 indicates that the exhaust gas exiting the catalytic converter is too similar to the exhaust gas entering the converter. A faulty or overloaded converter due to an unbalanced air/fuel mixture can cause this condition."

Anyone else have this code with our cars? What should I look for?

Thanks!

 

By the Way, my car just passed the 90k mark....could it be the cats?

 

P0420 is for catalytic converter efficiency

Either the CAT is bad or the O2 sensor - my money is on the O2 sensor.

 

The scanner checks the o2 sensor and it says it passes the test fine....weird...either way I reset the ecu so im waiting to see if it comes back up

 

Also, how bad is it to drive around if the o2 sensor is out? Could it mess up my car?

 

Scanner is saying that the sensor reading / resistance is within range, not that it's reading correctly. A lot cheaper to replace sensor than the cat.

Driving with a bad sensor is going to effect emissions and probably fuel consumption. That code is for Bank 1 (driver I think), you could swap sensors and see if the problem follows... then you'll have a better answer.

 

Thanks LMG....how hard is it to change the sensors? Can I do it with basic tools?

Also, I would basically have to buy 2 new sensors and if its not the sensors then im stuck with the ones i bought...

Should I just replace the Cat? I was thinking of going hi-flow cat either way....

 

Leaks can cause this fault also. The O2 sensors before the cats control the A/F mixture.
The O2's after the cats verify converter operation.