Hey all, I am relatively new here and this is my first time posting.
I have a 2001 F150 supercrew 5.4L. The check engine light has been on for a few weeks now. I had it checked out at Advanced Auto and they said its a generic code( could be any one of the sensors ), but the truck may suffer from poor gas mileage(come on now, its a 5.4L V8, gas mileage isnt that great to begin with).The truck runs fine, but its starting to get a little annoying looking at it. Does anyone have any other suggestions or advice. Thanks in advance.

 

What was the exact code number? That will tell us how to help you out.

 

Yeah exact code posted here. No one could even begin to guess without it!

 

10-4. I will hit up Advanced again and get them to tell me the code.

 

You can buy your own code reader for 20 bucks.

 

I don't think I've seen one that cheap before.

 

I've got one, it works fine.

 

Really, that's good to know. I'll recommend them myself

 

I have one to! it wont pull the codes out of my POS GMC van but it works great on every other vehicle I've tried it on! My brother in laws snap on scanner is the only one I've found that will retrieve codes out that van.

 

That's because it's a GMC, the little guy probably can't read that fast!

Just funnin. What year van? My '95 POS-10 Blazer has that OBD 1.5, it's stuck between OBD I & II. It was a transition year.

 

It's something GMC has going on with 1 tons. its a 2001 3500 Savana

 

Gotcha. Why make it easy, huh?

 

Well I went to advanced auto yesterday and the code reads P0171 Bank 1 system too lean. Hope this helps.

 

That is most likely from a vacuum leak. The most common on the 5.4's is the PCV hose at the back of the throttle body has rotted out. Check that first, if it's spongy then change it and clear the codes.

Whenever you have the codes read at the parts store, get the code numbers and post them here before buying. Those guys will always try to sell you some kind of sensor or something else, but they rarely know what they are talking about. Most of the time the sensors are reporting a problem and not causing the problem. Your fix will probably be less than 10 bucks in this case, unless you go to the dealer.

Good luck.

 

Thanks for the info jgger. I actually replaced that on our first trip camping last year. It rotted out like you said. So, im thinking that its not the cause this time, but I will check it again.