Error Code P0420 on 2000 TJ

[AaronPaul]

Bank 1 is the front catalyst off cylinders 1-3. You have a bank 1 sensor 1(pre cat) and bank 1 sensor 2(post cat). You have the same for bank 2 which is off the rear 3 cylinders. In my experience p0420/430 usually are not bad o2 sensors but you can certainly try to change them if you like.

So it is typically an indication of a bad cat? Sorry, this is new to me so thank you for being patient

 

[Fishtaco]

So it is typically an indication of a bad cat? Sorry, this is new to me so thank you for being patient

If its running right and you have no symptoms listed in the link hook up a scan tool to see what else may be there, if nothing just clear the code and see if it comes back.

 

[Lou]

So it is typically an indication of a bad cat? Sorry, this is new to me so thank you for being patient

Yes but changing the o2 sensors is very cheap compared to a new catalyst. The pcm has plenty of o2 sensor diagnostics. Very rarely will a failed or skewed o2 sensor pass the o2 sensor tests but only fail the catalyst test.

 

[AaronPaul]

Yes but changing the o2 sensors is very cheap compared to a new catalyst. The pcm has plenty of o2 sensor diagnostics. Very rarely will a failed or skewed o2 sensor pass the o2 sensor tests but only fail the catalyst test.

I don’t want to change all 4 if I don’t have to. I’m thinking bank 1 sensor 1 is the code I’m getting?

 

[AaronPaul]

If its running right and you have no symptoms listed in the link hook up a scan tool to see what else may be there, if nothing just clear the code and see if it comes back.

I’m getting an OBD tomorrow so I’ll run it again. I have to get it inspected so it has to run properly. Also, if something is broke I want to fix it not just run the Jeep anyway

 

[Fishtaco]

I’m getting an OBD tomorrow so I’ll run it again. I have to get it inspected so it has to run properly. Also, if something is broke I want to fix it not just run the Jeep anyway

Fair enough!

 

[AaronPaul]

Fair enough!

Last question. If I get a new o2 sensor are they universal? Or is each sensor unique to its position?

 

[Fishtaco]

Last question. If I get a new o2 sensor are they universal? Or is each sensor unique to its position?

4 different 02 sensors. Go to Rockauto website and go to jeep-Wrangler-2002- emissions-02 sensors.

 

[AaronPaul]

4 different 02 sensors. Go to Rockauto website and go to jeep-Wrangler-2002- emissions-02 sensors.

Thank you!! But I have a year 2000

 

[Fishtaco]

4 different 02 sensors. Go to Rockauto website and go to jeep-Wrangler-2000- emissions-02 sensors.

Corrected for you but you need to buy only NTK/NGK the reason it may be best to change all 4 is if you dont currently have NGK or Mopar you dont want to mix&match fail

 

[AaronPaul]

Corrected for you but you need to buy only NTK/NGK the reason it may be best to change all 4 is if you dont currently have NGK or Mopar you dont want to mix&match fail

Honestly not sure what I have. I’ve only had the Jeep for the month. I’m thinking Of replacing the top 2 to start. Thoughts?