Impala While undergoing many facelifts in its history, the Impala has proved itself to both civilians and police forces as one of the most capable 4-door cars GM has ever offered. Currently moving towards its 10th generation the Impala is one of the longest lasting and popular models.

2014 Chevrolet Impala
Includes: Bel-air
Platform: B-body & W-body

2003 impala check engine light code P0420

Thread Tools
 
Search this Thread
 
Old Feb 25, 2017 | 2:45 PM
  #1  
velouria's Avatar
Thread Starter
CF Beginner
 
Joined: Feb 2017
Posts: 3
Likes: 0
Default 2003 impala check engine light code P0420

I have spent a small fortune fixing various issues with this car. The current issue is that it will not pass inspection in Texass due to check engine light reappearing before drive cycle completes. It is always code P0420 & it always comes on while I am sitting at a ridiculously long red light. I'm running out of time and money to deal with this. If I have to replace the catalytic converter again, is there a particular brand I should look for? Also, is there possibly something else we're overlooking? From what I've read, this seems to be a common issue with this car. Thank you in advance for your help!
Reply
Old Feb 25, 2017 | 4:30 PM
  #2  
kevinkpk's Avatar
CF Monarch
10 Year Member
Liked
 
Joined: Jul 2011
Posts: 5,920
Likes: 140
From: kevinkpk
Default

Did you also replace the O2 sensor?
Reply
Old Feb 25, 2017 | 4:30 PM
  #3  
tech2's Avatar
Super Moderator
 
Joined: Mar 2011
Posts: 9,175
Likes: 521
Default

hold old is the present cat

p0420 can set due to bad 02 sensors, bad cat.

if there is an issue with fuel trim control; it could shorten the life of the cat.

do not put on a cheap cat. cheap cats have low cerium content, the oxygen storing element in the cat. cheap cats will set the p0420 not long after installation.
Reply
Old Feb 27, 2017 | 8:58 AM
  #4  
velouria's Avatar
Thread Starter
CF Beginner
 
Joined: Feb 2017
Posts: 3
Likes: 0
Default

Sorry if this ended up posting twice! I'm new here and not used to the setup yet. Yes, the 02 sensors were changed. It hasn't been a year yet since the cat was put on. That's why I was asking about a particular kind to use. Thank you for your help!
Reply




All times are GMT -5. The time now is 9:32 AM.