I have a 2005 Dodge Ram 1500 4x4. About 2 months ago, I got a check engine light. The code came back a bank 1 cat converter (PO420). I had that replaced, under warrenty. The other day, the light came back on. I used my superchips flashpac to read the code, and it was the same thing (PO420). A Dodge mechanic friend of my brothers said it would not be the converter again, but possibly an Oxygen senser. Anyone have any input on this subject? How tough is it to replace the O2 senser (s) by yourself, with moderate mechanical abilities? Thanks in advance for any info.



Oh yeah, the engine is the 5.7 hemi, and it has 38,000 miles on it.

 

Anyone?

 

An exhaust leak will cause some problem with the o2 sensor too. And yes you could have a bad cat. I would go back to the dealer and tell them the MIL lite came on, but its up to you if you tell the code is the same as before.

 

replacing o2 is super easy five min tops just need 7/8 wrench

 

Yeah but he shouldn't have to pay for it or crawl under there at all if its still in warranty. and yes a new cat can go bad that quickly. I believe the federal emissions warranty is 7 years, which both a cat and 02 sensor are covered by.

 

From my personal experience with the 0420 code........the dealer i took mine too said the fed warrenty was 8yr or 80,000miles. The dealer tried the 02 sensors and it didn't work. It was my converter/s and it was replaced. He saids it's possible that if your truck is driven short distances or the motor doesn't run very frequent, the cats can go bad often. I haven't had the code come up anymore. Like stated earlier, if you think it might be the 02's, their not bad to change at all.

 

Thought it was a 3/4?? Either way, replacing it is easy and they cost about 25-30 bucks. Another thing you can try to buying non-foulers and stuffing them with 0000 steel wool and putting the O2 on them and THEN in the exhaust pipe. Look in the FAQs at the top of this section for the non-fouler thread or do a search here on the board.

 

hey for everyone i dunno if it was just my sit or a general thing but i was getting the same code when i first purchesed my 98 dakota upon inspecting the cat i seen it had been cut open and im assuming gutted all i changed is the cat and my muffler i did NOT change either sensor and no code since no problems either hope this helps at all