Has anyone on here had problems with a blinking emissions light at certain speeds? I have a 2006 F150 with the 5.4L engine with 132,000 miles on it and have had a problem with the emissions light coming on when I reach a speed of 80 mph. The pickup will drive fine up unto this speed but when it reaches 78-82 mph the pickup will start shake/rattle and the emissions light will blink on and off repeatedly until you reduce your speed to around 60 mph and then the light will turn off completely. We took the pickup into the local Ford dealer for them to look at it. After they took a look they couldn't pull a code because there is no light that comes on until the higher speed. They told me that this was due to a bad tank of gas and this happens to prevent damage to the catalytic converter. They said it would be better once that fuel burned off. Well two full tank fills later the same problem persists. Just wondering if anyone has went through this and what course of action they took to fix it. Thanks

 

You are talking about the "Check Engine" light right -- just making sure.

A blinking check engine light is a bad thing-- if it's caused by an emissions problem -- I'm pretty sure that yours isn't.

The light should remain on until the code is cleared -- and if it was something bad enough to cause a blinking light , it should definitely have a code.

Codes are cleared only by
- getting reset via a scan tool or disconnectiong the batt -- they will reappear if the fault happens again.
- driving long enough with out a fault for the code to erase itself -- this usually means a couple of 'trips' with no problem ( a trip means something like startup -- get to temp -- run for so long --cool down)

So, I suspect that you actually have an electrical problem of some kind. Possibly your electrical power is cutting in and out when you go that fast -- that would make your truck run rough.

A dealer should certainly have a scan tool and be able to take a short ride and observe the OBD2 stuff while you're at speed. What they told you sounds like BS, but I wasn't there.

Good Luck,

hj

ps -- you probably should slow down a bit until you get things figured out.

 

The owners manual refers to the light as the "emissions system" but yes it is the check engine light.

 

A flashing CEL means a catalist damaging misfire . Severe damage can occur if you continue to drive .You should have it looked at soon .

 

Oh , and not the dealer you went to the first time ....