IamLexus

Not sure what the P stand for but I was wondering if I have to replace the catalyst converter or the o2 sensor?

Barryst

P0420 I would do the sensor first.
Its cheaper than the cat. and make sure to buy an OEM sensor.
You wouldn't happen to have an exhaust leak, would you? That would also trigger it.
-Try clearing the code,and see if it comes back.
I fought that code for a while (clearing the code, via obd2 scanner) until one day, I repaired a nagging exhaust leak. No more P0420 after that.
I don't think it hurts your car running with a P0420, but I don't like any CEL's lit consistantly for days on end.

-P could mean the code is Pending

Hope this helps...

IamLexus

the thing was when I bought this car the Check Engline lights, etc lightbulbs were burnt. So when I was repairing the green light (indicating your headlight is on) I repaired them as well. Basically I been trying it since Fall of 2009. My tachometer starts at 1.5K as well so I'm guessing its the o2 sensors? I haven't seen any leakage as well.

angmedic91

iTrader: (5)

Hope this helps you out bro, read carefully, several possibilities to look for and correct regarding this code. Also, "P" does not mean "pending"

http://www.obd-codes.com/p0420

acc

I got the same code on my car also. I don't want to spend a lot of money on a catalytic convertor.

IamLexus

When I floor it to go around 60 I can smell something burnt not a lot just a faint smell for about 8 second.