Help needed! Multiple cylinder misfire and traction light

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

Cfouts28

TYF Newbie
Joined
May 3, 2016
Posts
6
Reaction score
2
So I’ve got a 2007 Yukon Denali, 6.2 liter, truck was driving fine, then a few weeks ago my wife got off the highway, comes to a stop on the exit ramp. Goes to start going again and the truck immediately started to have a catastrophic misfire. Engine light flashing, traction/ stabilitrac light comes on, truck violently shaking. She turns it off right away. Highway is only like a mile from my house so I went and limped it home. Could smell raw gas real bad. It was incredibly underpowered and started smoking from under the hood. Popped the hood at home and the smoke was from the drivers side cat just cooking.
So things I’ve done, removed the cat to see if a clog caused the misfire, this wasn’t it.
Replaced all the coils, seems to be a little better but by no means fixed it.
Plugs and wires are probably a couple years old, but my wife puts like 5k miles a year on the truck, so I’m assuming those are fine.
Not sure where to turn from here
 

Geotrash

Dave
Supporting Member
Joined
Feb 16, 2018
Posts
6,434
Reaction score
15,955
Location
Richmond, VA
So I’ve got a 2007 Yukon Denali, 6.2 liter, truck was driving fine, then a few weeks ago my wife got off the highway, comes to a stop on the exit ramp. Goes to start going again and the truck immediately started to have a catastrophic misfire. Engine light flashing, traction/ stabilitrac light comes on, truck violently shaking. She turns it off right away. Highway is only like a mile from my house so I went and limped it home. Could smell raw gas real bad. It was incredibly underpowered and started smoking from under the hood. Popped the hood at home and the smoke was from the drivers side cat just cooking.
So things I’ve done, removed the cat to see if a clog caused the misfire, this wasn’t it.
Replaced all the coils, seems to be a little better but by no means fixed it.
Plugs and wires are probably a couple years old, but my wife puts like 5k miles a year on the truck, so I’m assuming those are fine.
Not sure where to turn from here
Need to read the codes or we're all just guessing. Get a Bluedriver dongle because you can read all of the modules with it.
 

OR VietVet

Multnomah Falls
Supporting Member
Military
Joined
Oct 8, 2014
Posts
20,758
Reaction score
36,732
Location
Willamette Valley
Yes! Codes! Please!

For what it's worth, I had something like that happen once with my 05 Z71 and needed oxygen sensors.
 

Joseph Garcia

Supporting Member
Joined
Aug 2, 2018
Posts
7,351
Reaction score
9,935
As stated above, the codes are needed for proper issue diagnosis and least expensive repairs.
 

ScottyBoy

Full Access Member
Joined
Jun 27, 2010
Posts
2,608
Reaction score
1,816
Location
Shreveport, La
Sounds like you may have lost an engine ground. You might have lost the ground for the coils and fuel injector harness. That would explain all your symptoms....
 

Forum statistics

Threads
132,364
Posts
1,866,745
Members
96,985
Latest member
LeanMachine

Latest posts

Top