I got a situation on my hands. I think my cat needs replacement and I know that the dealer would replace it for free under the emmisions warranty. I got the CEL code PO420 but some mechanic cleared the code. Now the dealer wont replace the cat because they said they needed the CEL to be still on. Its been like 3 weeks now and haven't gotten the code again. Is there a way too restore the code or something? I drive the car mostly everyday, i dont want to do any damage if i keep driving without fixing it. I have a 2004 auto. Any suggestions?

 

Before you take the car in, disconnect the rear O2 sensor so the code will come on when the car is running. Then reconnect it.

 

is it really that simple? damn i just keep learning in this forum. nice. wait that sensor is in the cat right? i got to look up how to get to it

 

Jack-up car
Install jack stands so car doesn't fall on you.
Find sensor sticking out of cat and follow wire to the disconnect nearby.
Disconnect wire.

 

Oh cool. well ima try that probably 2morrow since dealer wont open till monday. I'll post if it works or not. Thanks alot grasshopper!

 

couldn't you also just drive it for 50 miles and if there really is a problem it should trigger the CEL

 

No guarantees... especially with an '04.
Some '04s can run a mid-pipe with no CEL.

 

well i tried disconnecting to sensor but i couldnt it. it looked like the tab was a little melted. Now the tab is broken and it wont come out. So im guessing i have to buy another sensor and replace that one.

 

try driving the car like I posted above^^^

 

i did that once already but nothing..and its been like 4 weeks now since they cleared the code. i also drive it mostly everyday.

 

seafoam your engine to bring the cat under efficiency. (the ecu will think this)
then take it in and have them replace.

hopefully this works, it just came up in my head as a good possibility