Jeep Garage  - Jeep Forum

Jeep Garage - Jeep Forum (
-   Grand Cherokee - WK (
-   -   DTC codes (

VanMan1967 04-15-2011 07:06 AM

DTC codes
Hi all,

I damaged the cat boxes and middle silencer on my 5.7 Hemi WK with some enthusiastic off-roading. I drove with the following codes for about 6 months, before finally acting on it yesterday:
P0300, P0420 & P0430

I cut out the 2 cat boxes, one empty and one blocked and replaced it with pieces of pipe. I also replaced the big silencer underneath the car with a smaller unit. I reset the DTC codes and drove about 100km before the P0420 & P0430 codes returned.

Does this actually cause damage or is is only being annoying? Does it affect my car's performance at all? If not, how can I permanently reset it?


2005JGC 04-15-2011 02:59 PM

Re: DTC codes
p0420 and p0430 are catalyis efficiency codes... it uses the downstream O2 sensor to see if the catalyst is functioning or not. When they switch like your upstream o2 sensors it tells your computer the cat or in your case cats are not doing anything.

So until you put catalytic converters in those codes will remain.

05WK 04-17-2011 01:35 PM

Re: DTC codes
Fastman sells a product that eliminates those codes, supposedly. I dont own one myself tho.

jeepgcoman 04-17-2011 06:13 PM

Re: DTC codes
Having those codes should also render your MDS inoperative, if you care about having it.

All times are GMT -5. The time now is 09:44 AM.

Powered by vBulletin® Version 3.8.8
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Copyright 2012 - JeepGarage.Org
The Jeep Grand Cherokee Owners Community