Express, Savana & G-Series Vans Offered in both a full size van, or a large box truck, the Express is the modern GM workhorse.

Chevrolet Express
Platform: GMT Van

2005 Express With 430,000 miles

Thread Tools
 
Search this Thread
 
Old Sep 24, 2018 | 2:57 PM
  #1  
beaufosheau's Avatar
Thread Starter
CF Beginner
 
Joined: Sep 2018
Posts: 3
Likes: 0
Default 2005 Express With 430,000 miles

My Express just got to the 430k mark and I just started experiencing error codes. How bad does this look? The van runs great (other than the apparent codes).
Error codes.
Reply
Old Sep 24, 2018 | 9:21 PM
  #2  
geo1's Avatar
CF Senior Member
 
Joined: Aug 2018
Posts: 357
Likes: 2
From: Adirondacks,ny
Default

It's blurry,can you write them out?
Reply
Old Sep 24, 2018 | 9:48 PM
  #3  
loopedr1's Avatar
CF Junior Member
5 Year Member
Liked
 
Joined: Sep 2018
Posts: 88
Likes: 13
Default

i would clear the codes.....get a good tank of gas....and check or replace your gas cap....then see what comes up.....a bad gas cap could cause the evap leak causing the engine to go lean then tripping the other codes.......it could just be a simple fix
Reply
Old Sep 24, 2018 | 9:53 PM
  #4  
beaufosheau's Avatar
Thread Starter
CF Beginner
 
Joined: Sep 2018
Posts: 3
Likes: 0
Default

Originally Posted by geo1
It's blurry,can you write them out?
Yes! Sorry about that.

P0300 - Random/multiple cylinder misfire condition.

P0420 - Catalyst system efficiency below threshold.

P0430 - Catalyst system efficiency below threshold.

P0455 - Evaporative emissions system leak detected (large leak).

I understand the basic code descriptions however I don’t really know how worried I should be or what a good course of action would be in order to keep this thing going strong to 500k.
Reply
Old Sep 24, 2018 | 9:56 PM
  #5  
beaufosheau's Avatar
Thread Starter
CF Beginner
 
Joined: Sep 2018
Posts: 3
Likes: 0
Default

Originally Posted by loopedr1
i would clear the codes.....get a good tank of gas....and check or replace your gas cap....then see what comes up.....a bad gas cap could cause the evap leak causing the engine to go lean then tripping the other codes.......it could just be a simple fix
I’ll definitely try that. Are there any cons to clearing the codes? Or does that just allow you to make sure that the problem is real if/when the error codes return?
Reply
Old Sep 24, 2018 | 9:58 PM
  #6  
geo1's Avatar
CF Senior Member
 
Joined: Aug 2018
Posts: 357
Likes: 2
From: Adirondacks,ny
Default

Now it comes in clear?for the 300,I would check fuel pressure,intake manifold leak,man, your doing everything right with that milage
Reply
Old Sep 25, 2018 | 8:18 AM
  #7  
StanVan's Avatar
CF Veteran
15 Year Member
 
Joined: Jul 2008
Posts: 1,306
Likes: 23
From: Harrisonburg Virginia
Default

I had a bad gas cap once, and had no way to clear the codes after I replaced it (I was out of town). I was told it might take up to 100 miles before the codes cleared themselves.

In other words, clear the codes.
Reply
Old Sep 25, 2018 | 10:34 PM
  #8  
mountainmanjoe's Avatar
Super Moderator
 
Joined: Feb 2017
Posts: 6,207
Likes: 689
Default

If the misfires continue, then check up on your ignition system.
Reply
Old Sep 26, 2018 | 3:59 PM
  #9  
ChevyVanMan's Avatar
CF Active Member
 
Joined: Mar 2017
Posts: 120
Likes: 1
Default

Plugged cat system maybe.
Ken
Reply
Old Sep 30, 2018 | 4:26 PM
  #10  
loopedr1's Avatar
CF Junior Member
5 Year Member
Liked
 
Joined: Sep 2018
Posts: 88
Likes: 13
Default

the codes wont clear themselves........go on line and buy an obd2 reader....they are about $20......then you can clear the codes .....if they return fast you have a problem....sometimes a little problem like a gas cap can cause a cascade affect with codes....
Reply



All times are GMT -5. The time now is 5:51 AM.