I have a 2001 Ford Explorer Sport Trac. It has 80,000 miles and have owned it since new. Recently the gas mileage dropped quite a bit. Other than oil changes, and spark plugs i havent done anything to it. I put on an airaid intake kit i got on sale from fourwheelparts. It has Bosch Platinum +4's. What should i look at doing to it.

Could it be the O2 censor, would the fuel filter have anything to do with it? Any help is greatly appreciated

 

Have you pulled the codes yet? If they don't reveal anything, start with the simple stuff.... fuel filter, wires, ..etc. Did the mileage go down before or after you put the intake kit on?

 

Does that kit have a re-useable, oiled filter in it?

I've read of some issues with the oil from these coating certain emmisions components up and making them react incorrectly.

Maybe not this problem, though. I think the main concern I read about was that sensor in the air duct (IAC ?) getting slimed and causing idle problems.

-Larry

 

A few places to look. Other's in this forum have reported items such as:

1) bad fuel regulator giving too much pressure at the injectors
2) bad MAF sensor, not a dirty one, reporting more air flow than actual thus PCM gives more gas
3) bad O2 sensor. Mine indiacted a lean condition thus PCM gave too much gas to one side.
4) Bad inition components causing engine "missing" - although you would notice the miss too not just the lapse in fuel economy.

Sorry Larry, the IAC has little effect on overall gas mileage since it simply monitors a small orifice of air flow into the manifold at idle. You'd notice a big drop in gas mileage by malfunction of one of the other closed loop control components that are used all the time by the PCM.

 

Also check for fuel being sucked into the intake manifold through the fuel pressure regulator vacuum hose.

 

My view is that if your fuel economy drop occurred somewhat after putting in the bosch +4s then I suspect the plugs. It has been established that the very best plugs for a Ford are oem ford plugs -bar none. It has also been noted that bosch +4s do not seem to function well in ford engines. That plug was designed for a VW or Audi or BMW motor. They work very well in those applications. Similarily using a ford plug in those cars is also a no-no. The bosch single plat will work OK however. Though it is not double plat and will wear out quicker than a double plat.

John

 

Kind of generalizing on the plugs don't you think? Well I use double platinum plugs in my 4.0 and I just put some in my 5.9 Durango. Reason is the life extension. Not because Bosch plugs don't work. I looked at the 4 pronged goofy looking Bosch plugs and thought - no, just more sharp corners to promote detontation. You're nt going to get 4 sparks out of it. Electricity takes the path of least resistance and it will ground to one electrode or another and maybe never to one of the 4 electrodes. just depends on the physics at the time. I see the Bosch 4x's as just a marketing campaign. Show me the data that they work better or "don't" work in Ford engines, and then we can talk.

 

Pilot: Can you relate the fuel economy drop to anything that happened to your Explorer? I have heard of cases where the vapors from the oil-type air cleaners can coat the MAF sensor (air flow) causing erronious readings to the computer. You can clean your MAF with electrical contact cleaner being very careful of the delicate wire.

Many have proclaimed having various difficulties with the Bosch spark plugs in their Fords. If the behavior change to your Explorer started around the time of the spark plug change it is possible that a new set of Motorcraft PP's could help restore your economy.

As you mentioned, you may very well have a "lazy" oxygen sensor. There are tests that can be used on it - check the threads for that procedure. All you need is a vom.

With some regularity, I fight the carbon build up in our 4-cylinder Rangers due to all of the city driving. Again, in the threads there is a procedure to decarbonize your engine. While the thread is addressed to the 4.0 6-cylinder engines, the process and results would be the same.

Again, scan for codes and follow up on any that are present. If you need specific pinpoint test information for any circuit, Ken00 seems to have them available.

Keep us posted.

Russ

 

The MAF sensor is actually what I was trying to come up with at the time, but I agree. It's probably not that.

I do know that the oil-type filters can cause MAF sensor issues.

-Larry

 

You go RangerRuss. That's where I was trying to go. I just got there via the wrong part

-Larry

 

Well i noticed it far before i put the intake kit on, so im sure thats not it.

 

Pilot,

Pull the bosch plugs, put in some oem ford plugs and get on with it! You may have other problems, any codes? With the fresh motorcraft plugs you can rule out most ignition problems. After the plug install try resetting the ECU. I think it can be reset by lifting the battery cable for 30 minutes or so. If wrong someone please correct me...it worked on my 92, 95 and 97 explorers!
John

 

Pilot,
Find a good scan guy and pay him what he's worth for his time & equipment. You will find this little bit of money well spent and you wont have to deal with the guessing game. Unless your up to pulling codes yourself. But it helps to have the fuel analyzer hooked on as well.

Ken

 

Ok, Now my 2 cents. Pilot815, Go down to NAPA get you a can of sea-foam (red and white can) take the vac. line off the brake booster put 1/3 of a can in NOT ANY MORE !!! and let it sit 5 min-/+ start the truck up, it my not start first shot. Let set 1-2 min. and try starting again. The truck will start and smoke really bad. Go out and drive around the block till it stops smoking. You may need to do it again in a week or two. You can add it to your gas to. Give it a shot, $10 buck may fix the problem.

 

What the heck will the sea foam do??