First of all here's some info about the truck... 2002 ram 1500 with a 360 5.9l (3rd gen body style 2nd gen motor). It's got 163k kms, (100k miles) airaid intake, msd coil and wires, superchips 3865 set on mileage xp, catback exhaust and the rear 02 sensor changed 5000 km's ago.

Now I keep getting the code p0420 (catalytic converter effiency) about every 200 - 300 km's after resetting the PCM (Disconnecting Battery for awhile) and I'm tired of the CEL coming back on. So now here's the question... what should I do?

1. Use the Spark Plug Defouler trick on the rear 02 sensor?

2.Gut the cat and use the Spark Plug Defouler trick on the rear 02 sensor?

3.Cut the cat out, put in straight pipe and use Spark Plug Defouler trick on the rear 02 sensor?

4.Replace the front 02 sensor?

5. Get a new OEM cat? (it's the Y pipe kind where the cat is part of the Y pipe and is kinda pricy)

6. Get a hi-flow cat and fabricate it up to the existing cat back and headers? (Still kinda pricy)

7. Other? please specify

Things to keep in mind is that I don't want to lose any performance and the light NEEDS to STAY off... for that code anyways.

And I have one more problem if you feeling like helping out some more... Whenever I press lock or unlock on the door lock switch or the lock button on my keyless entry, only the front locks operate and the rear ones don't move at all... Any ideas as to a fix?

Thank you very much for your help. It is greatly appreciated

Busterbrown

 

The warranty on your 02 Cats is 100K miles. If your under that you may look into a free warranted one.

That code means you have a bad cat. The defouler trick may work. If you do that gut the cat first. You sure don't want to burn a valve cuz of a clogged cat.

Here is a good little site:
http://www.obd-codes.com/p0420

 

Nah I'm not under 100k miles...

So one vote for defouler and gut the cat.

Any other opinions?

 

I say gut and defouler too

 

Long Tube Headers, omit cat completely, do the non-fouler trick and change the damn tune on that tuner from XS Mileage to PERFORMANCE! Do you realize the performance gains that would give you? Especially with headers, the SC really wakes up a 360 in performance mode, best gains on a gasser with a tune I've ever seen. C'mon man...

 

YEA def agree with the Hammer..i have the same year and engine as you and i would never run anything but performance except when it gets snowy, then i will bump it down for winter, but you get soo much more outta the performance tune..but i have the non foulers in my truck bc i have the high flow cat on my truck and it always comes on especially when the weather is cold outside..but it is totally up to you..you have any other questions let me know

 

Count me in as another vote for the non-fouler.

 

So there's a few votes for gut/de-fouler.

02dodgeram5.9 so you're saying with the defouler trick and a hi-flow cat you're still throwing a code? Or you put in the defoulers after the code came on a couple times with the hi-flow cat? Also how did you put in your hi-flow cat? Did you have to fab up your own y-pipe?

Also are there Long tube headers for this truck and who sells them? I know they'll be a little pricy it'll be good to finally get rid of the cat and get a nice performance gain as well.

 

No b4 i put in my non fouler i was throwin that code..but now i have the non fouler in i am not throwin that code. i used the existing y pipe..i just took it to the muffler shop and he welded it right to the y pipe..have a 3" in 3" out magnaflow high flow cat..