Hey guys, I started my truck this morning and noticed the check engine light staying. Not blinking, just on. So I'm only at 250 miles on the odometer, it's a 6.2 gas. The truck runs and shifts flawlessly, I'm wondering, I bought the truck out of Boise area and they filled it for me. I live at sea level here in Oregon. Is the gas less octane in Boise ? And could that cause a light? I plan to run over to Napa and borrow there code reader after work. But just wanted your thoughts, thx!!

 

It's not a fuel octane issue. The only sensor for that is the knock sensor and all that happens there is the computer adjusts timing until the knock goes away. The only time the engine light will blink is when something is occurring that will destroy the catalytic converter. The steady light means something isn't right in your emission control system. It could be one of hundreds of things. Some will put you on the side of the road, but most won't do that. You can scan for the code, but unless something just came unplugged and you can identify it, you're going to take the truck to the dealer for a warranty repair.

Edit: I want to add that no matter what, DO NOT erase the code that set the light. Erasing the code will never, ever fix the problem. If you erase the code to turn off the light, you erase the code, the code history, the freeze frame data, and pending codes. If you turn off the light and then take the truck to the dealer, they'll just tell you to come back when the light is on. Also, if what turned on the light was a hiccup that won't be coming back, the light will turn itself off, usually after two drive cycles.

 

Boise is at 2700 feet elevation, so I suspect their “regular” gas is 87 AKI, just like yours on the Oregon coast.

Check your truck’s gas cap before going over to NAPA; see OM pages 194 and 188.

Finally, what is your truck’s trim level (I.e., XLT or Lariat)? Warning indicators vary between trim levels.

HTH,
Jim / crewzer

 

Make sure the gas cap is nice and tight. Fought that on a 2011 F250. I needed the code reader to turn off the CEL

 

I had my check engine light come on twice in a year. Both times, I had just filled up with gas and parked downhill. My code reader said it was something to do with the evap system. I cleared the code and had no problem.

 

My trim level is an XL, stx package. Thx for the posts!!

 

I had the XL trim as well. If you get an inexpensive bluetooth OBD II reader and download an app on your phone, you'll be able to read the codes and turn off the CEL

 

OK. I believe (not 100% sure) that the Lariat+ trim levels with the high-res instrument display get a “loose fuel cap” display icon.

I hope you’ll update is on the resolution.

Safe travels,
Jim / crewzer

 

I definitely will, I was unable to get to Napa as I had to work mucho overtime tonight. If the stars align, I will sneak over tomorrow at lunch! Thx

 

Hi guys I checked the code and it's po456, the Napa scanner didn't say anything else. Anyone know what this is? Thx!

 

Code P0456 indicates a small leak detected in the Evaporative Emissions (EVAP) system. The evaporative emissions (EVAP) system is designed to prevent fuel vapors from escaping into the atmosphere.

Another words Gas cap.

 

Thanks man! So I have checked it many times for tightness, mabye look at the gasket or.....? Also, will the check engine light go away on its own?

 

It never did on mine.I bought this so I could clear the code to see if the new gas cap worked, and it did.