I have a 91 explorer with about 218k miles, yes that many miles. I do about 50kmiles a year from my job, becuase of being on the highway 90% of the time.

But anyways, I have had this exp. since march 2000 and I couldnt ask for more out of a ford let alone a SUV. I have had my problems with it here and there, but who doesnt when running it as much as I do.

First thing to go was my EGR, then my fuel reg., then my alternator, then the door lock actuator on the driver side, then the o2 senser. Other then that nothing major has gone wrong, everything that has happened so far it still kept running long enough to get me home.

I guess the questions could start now, I have just recently changed my plugs and wires, fuel filter and had the computer checked. I used to use about 5 gallons per 100 miles which is my mileage at work for the first couple years, last couple months I've noticed I have been using 6-6&1/2 gallons now. I am useing alot of gas more then usual(which is why I had the updates done recently), I had smelt gas fumes the other day while the truck was running standing next to the driver side rear tire.

I had looked underneath and saw/smelt fumes coming from the connection to the gas tank opening(where you put in gas), I also saw gas around the hose where the clamp is holding it on(also drops of gas on the ground). Is this why I am losing gas, I heard that the gas tank is pressurized and thought that it could be pushing it out of that lose connection?

Also I have 2 cat. conv. it looks like, two 1' long connectors that are buldged(looks like small cat. conv.). How would I go about checking to see if they are clogged, I can't take it into a actual muffler shop at risk of them finding out I may have gutted conv. They would be required by law to put new ones on before I left I found out, I'm thinking I have gutted conv. becuase of the deep sound that my exaust makes(ford dealer installed stock muffler).

This is a book I'm sorry, but I thought I should give some detail on certain things to get my point across. If someone could help me I would be thankful.

 

Lets take your questions like this.
1. Leaking liquid fuel is not good and should be fixed as soon a possible for safety sake. The tank is not pressurized, but is designed to not let expanding gasoline fumes to escape into the atmosphere. The gas cap is a 1 way valve letting air into the tank as needed, but blocking fumes from exiting to air. A hose runs from the tank vent tube (On the top) to che charcoal canister to trap fumes which are then drawn off into the engine and burned under computer control of the canister purge valve. So unless your leak is large, I doubt it is source of higher fuel consumption.
2. Cat converters/ mufflers, when blocked, will cause a severe drop in engine performance, almost to the point where vehicle will not move out of its own tracks and be a real dog. There is generally an accompaning sound change in the exhaust and it sounds more like a jet engine exhaust whine.
I doubt yours are blocked or gutted just by the deep throaty sound of your exhaust. My 91 with 208K miles sounds much the same and I know it is all original except for the muffler which has been changed twice now.
3. Mileage reading around 17MPG sounds pretty normal, especially if yours is 4WD. Others have reported in the low 20MPG range. Mine doesn't start to approach 20 till 2nd or 3rd tank of gas on a long continuous trip.
4. Tune up items you mentioned sound fairly normal except for the EGR part. 91 does not have EGR on the engine, so if someone said they replaced yours, you got ripped.
Dialtone

 

I may have been thinking of my EGR from the 86' chevy blazer I had or the 80' toyota, I had so many under hood problems with the past 3 cars i have owned from working this job its a little confusing when trying to remember which I had done to what.

The gas milage was pretty good before it started having problems, I could do about 400 miles on a full tank with out needing to refuel as long as it was on the highway most of the time. It is in a very noticeable gas useage right now, I think i went from half a tank to just a little below the 1/4 tank mark in a 60 mile round trip(figuring each 1/4 tank section on the gauge is 4.5 gallons on an exp.).
That is very unusual for my truck seeing that just 3 months ago I was only using 1 1/2 gallons just to make that trip I do every day. No warning lights are on and I'm not losing any power that a 200k+ exp. wouldn't be showing signs of.

Please.... 4.5-5 gallons in a 60 mile trip that isnt even excursion gas mileage if you think about it on the highway. I started having these problems in my 86 blazer is why I traded that in for the exp., I was getting about 10 mpg in that when I took it in to the dealer and they didnt know what was wrong.

I have noticed that my muffler has seperated from its fitting, connecting it to the back of the extention coming from the cat. conv.. Even tho I have decent amount of passage coming through the muffler would it still be clogged?