Question about 1999 GMC Yukon
Vehicle needs a Primary or first position Oxygen sensor, bank one just means it's the O2 sensor before catalytic converter
Posted on Jul 02, 2009
I have 1998 gmc pick up truck and has code po 420
Posted on Dec 23, 2009
a 6ya expert can help you resolve that issue over the phone in a minute or two.
best thing about this new service is that you are never placed on hold and get to talk to real repairmen in the US.
the service is completely free and covers almost anything you can think of (from cars to computers, handyman, and even drones).
click here to download the app (for users in the US for now) and get all the help you need.
Posted on Jan 02, 2017
What this means is that the three way catalytic converter is not doing it`s job and it needs to be replaced.First check the exhaust system and make sure it is not bent or has holes.If it`s good then make sure the rear o2 sensor is working properly.If that`s good the you will have to replace the cat.converter.Good luck.
Posted on Dec 06, 2009
Testimonial: "that was an amazingly fast...I'm going to have my brother check that out this week...thank you so very much. "
Tips for a great answer:
Nov 01, 2012 | Dodge Cars & Trucks
Jun 02, 2012 | 2001 Cadillac Seville
Jan 26, 2011 | 1997 GMC Jimmy
Nov 17, 2010 | Mercury Sable Cars & Trucks
Feb 24, 2010 | 2002 Chevrolet Monte Carlo
Dec 06, 2009 | 1998 Pontiac Grand Am
Sep 28, 2009 | 1998 Saturn SC
Mar 29, 2009 | 1997 Toyota Camry
Dec 11, 2016 | 1999 GMC Yukon
667 people viewed this question
Usually answered in minutes!
Step 2: Please assign your manual to a product: