GMowner

Today, as I was driving, my engine light started flashing out of the blue. It flashes for about 2 minutes and went away. It freaked me out because I know it can be a serious problem. I plugged in my code reader and it gave me P0156. I believe that is the O2 sensor (Bank 2 Sensor 2). Then a couple of hours later the engine started flashing again. And, like the first time, flashed for about 2 minutes and went away. This is really worrying me. Can it be the O2 sensor that is causing the engine light to flash, or is it a misfire? The reason I suspect it to be a misfire is because a little over a year ago, my engine light was flashing, and it continued to flash. Turns out, I had to change new spark plug and new wires, and soon after a new catalytic converter because it got damaged from driving with the misfire. Any help would be greatly appreciated. I love my chevy suburban, but all of this engine light flashing is making me regret buying GM. And I only owned the truck for 2 years.

Chevrolet Customer Service

Hello GMowner,

We're sorry to hear about this check engine light concern you're experiencing with your Suburban. Have you contacted your dealership about this? As we are not trained technicians, we rely heavily on our certified dealerships to address any and all vehicle concerns. If you're interested in setting up a diagnosis appointment, please send us a private message and we'd be happy to help.

Best,

Chelsea D.
Chevrolet Customer Care

kevinkpk

O2 sensor won't cause a misfire, it is in the emissions system. O2 sensors look at the O2 on both sides of the cat. If you have a misfire you'd get a code in the "3"s, i.e. PO301 would be misfire cylinder #1.