gmc forums   gmc forums
Go Back   GMC Forums > GMC Vehicles Currently In Production > GMC Yukon Forum

GMC Yukon Forum Forum for discussions regarding the GMC Yukon


ATTENTION: We're looking for moderators. Is anyone interested?
GMC Forum: Problems With My 2003 Gmc Yukon Denali?
Reply
 
Thread Tools
  #1  
Old 02-07-2010, 01:02 PM
MAXD MAXD is offline
Junior Member
 
Join Date: Feb 2010
Posts: 6
Default Problems With My 2003 Gmc Yukon Denali?

I Have Had A Ton Of Problems With My 2003 Yukon Denali. I Had A Miss Fire On The Number 8 Cylinder And I Did The Following, Checked The Fuel Pressure (56 Lbs), Changed The Coil Pack On That Cylinder , Changed The Wires(msd), Plugs(acdelco Iridium) And Fuel Filter. I Had A Code Pop Up That Was P0308 And After I Changed The Plugs It Changed To P0300. It Still Idles Like It Has A Misfire And At Low Rpm But Once You Start Going It Runs Fine, Like Driving Down The Highway. Any Ideas?
__________________
Powered by Yahoo! Answers
Reply With Quote

  #2  
Old 02-07-2010, 01:02 PM
Frankie Frankie is offline
Junior Member
 
Join Date: Dec 2009
Posts: 12
Default

In some cases, the catalytic converter has gone bad. If you smell a rotten egg smell in the exhaust, your cat converter needs to be replaced. I've also heard in other cases the problems were faulty fuel injectors.

Random misfires that jump around from one cylinder to another (read: P030x codes) also will set a P0300 code. The underlying cause is often a lean fuel condition, which may be due to a vacuum leak in the intake manifold or unmetered air getting past the airflow sensor, or an EGR valve that is stuck open.
__________________
Powered by Yahoo! Answers
Reply With Quote
  #3  
Old 02-07-2010, 11:30 PM
Molson02536 Molson02536 is offline
Senior Member
 
Join Date: Dec 2009
Location: K/W Ontario Canada
Posts: 3,098
Send a message via AIM to Molson02536 Send a message via Yahoo to Molson02536
Cool

Quote:
Originally Posted by Frankie View Post
In some cases, the catalytic converter has gone bad. If you smell a rotten egg smell in the exhaust, your cat converter needs to be replaced. I've also heard in other cases the problems were faulty fuel injectors.

Random misfires that jump around from one cylinder to another (read: P030x codes) also will set a P0300 code. The underlying cause is often a lean fuel condition, which may be due to a vacuum leak in the intake manifold or unmetered air getting past the airflow sensor, or an EGR valve that is stuck open.
Frankie is in the right direction about the engine running Lean when the engine is at idle. Try Cleaning you MAF sensor and make sure your running the correct octane rating your Yukon's engine is suppose to run on. 87 octane unleaded regular gasoline is the recommended fuel used on the 6.0 liter Vortec on the 2003 Denali.
Reply With Quote
Reply

Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump



All times are GMT -5. The time now is 04:57 AM.


Powered by vBulletin® Version 3.8.8
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
gmcowners.com recognizes that "GMC", it's logos and various model names and numbers are registered trademarks of the General Motors Corporation. These terms are used for identification purposes only. gmcowners.com is not affiliated in any way with the General Motors Corporation, GMC or any other company listed herein. All information on this site is the opinion of its members and not the opinion of the site itself. 2014 Madison Ross Media Group. All rights reserved. Content published on GMCOwners.com requires permission for reprint.
MADISON ROSS MEDIA GROUP MARKETPLACE
Need products for your GMC Truck? Check out your options at the links below:

No special deals available at this time...