I have a 1999 5.4L F150 and my service engine soon light has been coming on for several weeks. Called the dealer and they told me that the gas cap was not on tight enough. I bought that for a few weeks but then I found on the web were you could by a scanner to tell you what was wrong. The scanner is made by AutoExray and the codes that I got were 0452 Evaporative Emission Control System Pressure Sensor High Input. And 0453 Evaporative Emission Control System Pressure Sensor Low Input.

I did add a K&N FIPK six months ago I don’t think that is causing it. Ford says it could be hose leak.

Anyone seen any of these errors??

Thanks,,

Taterman

 

It could very well be a hose leak I put the same K&N fipk on my truck and the hoses they give you weren't long enough.Maybe a little soapy water around where hoses clamp start up truck and look for bubbbles.

 

Barlitz,

I hope that is what the problem is. i installed the FIPK about six months ago. The problem has just started. I will check the connections.

If i need to take it back to the dealer do you think i should take the FIPK off. Does void the Warranty.

Thanks again,,

 

Actually, there is a sensor in the fuel system that looks at pressure in the fuel system for evaporative emission control purposes. Its underneath, back by the gas tank I think. I have not seen it myself yet, but I want to look for it. It is a 3 wire sensor, and will have a hose attached. I expect it to be in the vapor hosing, not in the high pressure line from pump. You may want to look at those hoses up there. Also, I have heard that a gas cap that does not seal tight can cause this. It would be letting out those "harmful" gas fumes, polluting the environment. So the new OBD-II standards make car and truck manufacturers have an automatic way of flagging failures like that. Better living through Better Government!

 

Granpa,

I was looking in my Chiltons book and i saw where the sensor is. I will look at the connections. hopefully it will be something simple. I will also buy a new gas cap. I have put gorilla pressure on my current on with now luck. I am trying to keep from taking it back to the dealer. I have not had much luck with them.

Thanks!!!!!!

 

More info. Sensor mounts on top of gas tank, real hard to see. Lots of hoses to check, 2 from tank to carbon canister mounted above rear axle, and hose from there to metal vapor line to underhood. Also hoses at the Vapor Management Valve mounted on firewall, just above brake booster. At least the VMV is easy to get to!
I noticed that one bigger hose from tank to the canister was pretty floppy on mine. Maybe that one might be more likely to have problems at the end.

 

I checked all of the connections this weekend. They all looked ok. I then cleared all of the codes out of my computer and drove my truck around this weekend. The codes have not come back, yet. I hope that it was just a loose connection or something. thanks for your help.

 

It is most likely the gas cap. My non-Ford truck threw the same code. The light would be on for a couple of days, then go off. The mechanic I use told me it's almost always the gas cap when this code shows up. I changed (about at $6 I think) cleared the codes and the problem is gone. Since your truck is the same age as mine with more mileage, I would suggest changing the cap before you go crawling around under the truck too much. It's cheap, and I'll bet those sensors aren't.......

Good luck!

Jeff