A couple questions....

[krooozn]

Over the weekend I took my 2007 Sport Trac into the local muffler shop and had them replace the stock exhaust with a flowmaster. Which I might add sounds really good...anyway....I didn't opt to disconnect the battery, figured I would just let the truck relearn on it's own.....well saturday afternoon, went out to run some errands and the truck wouldn't start....come to find out my negative battery cable was the issue....so needless to say once the cable was disconnected from the battery for over a half hour or so, it cleared the computer of the old driveability settings, so now I am in the process of letting the computer relearn the idle and trim pattern. My question(s) are these....first....how long will it take the computer to relearn the pattern?...second.....will I see any mpg difference with the flowmaster versus stock? I am in hopes of gaining maybe 1-2 mpg.....but my biggest concern is the time for the computer to catch up.....the truck seems to be running just fine, no rough idle or high rpms....and it seems to be shifting normally as well.....I read in my owner's manual the steps to relearn the computer, but they made very little sense to me....so maybe someone here could better explain it to me, in more user friendly terms.....I'm not stupid or dense, but sometimes I don't quite comprehend what I read...

Thanx...Anita

 

[jrford]

It will take a bit to relearn everything, more or less your doing the right thing. I'd also get on the highway and set the cruise for a bit. Found this in a TSB.

TSB instructions:
Drive unit to perform adaptive shift strategy learn.
Accelerate from rest with light throttle. The 1-2, 2-3, and 3-4 shifts must occur at engine speeds between 1300-1800 RPM.
Continue to accelerate gently to 50 MPH (80 Km/h) so that the transmission shifts into 6th gear.
Brake gently to a complete stop and hold foot on brake for at least 15 seconds.
Repeat Steps (a-c) a total of five (5) times.

 

[EARL97850]

I didn't do any exhaust work like the original poster did but I just had my transmission serviced and re-flashed and this exact thing was done by the service tech after things were buttoned up and ready to test.

I was told that things might act a little funny for a week or so because the truck is learning things all over again.

Hope this helps.

Cya

 

[JohnnyO]

Typically it takes about 100 miles for the tranny to relearn itself. After I put the Gibson system on I picked up as much as 3 mpg on the highway. City mpg is no different than before.

 

[HAWK99GT]

Anita - is your ST a V6 or V8?

If it's v8 like mine, you'll probably get a couple extra miles in improvement in the gas. Definitely takes off a lot nicer. V6 probably gets better gas mileage just cause it is v6.

I didn't notice anything spectacular as far gas mileage, but it does sound nice

 

[krooozn]

Thanx for all the replies....I just got done with my first tank of gas after the exhaust mod and the computer reset. I put about 350 miles or so on that tank and according to the mpg that the computer generates, it said I got 19.9 mpg on that tank. I have been running nothing but BP brand gas since that is what is recommended according to the gas cap, but the tank I am currently running isn't BP and I have about 280 miles on it thus far with a half tank left and the computer is stating the mileage right now at 19.4 mpg. I believe that prior to the exhaust mod and reset, I was averaging most times 18.0 to 18.5 mpg on a tank. So hopefully as time passes the mpg will pick up a little more. I have noticed since the reset, the truck seems to idle a little lower than it did originally and from a cold start, it idles slightly higher and then gradually kicks down to the normal Idle rpm....which is at about 700-800 rpms now....anyway...wanted to give an update on my progress since all of you were kind enough to reply to my post. I also wanted to say that about 2 weeks ago I had the transmission fluid flushed and filled and had them do the tranmission flash while they had the truck....have notced better shifting and more pickup since this flash....so hopefully this will help with the mpg a little too.

By the way....my ST is the V6....

Thanx again...Anita

 

[HAWK99GT]

How long did you leave your battery disconnected?
And just like i figured, a V6. They always get better gas.

 

[krooozn]

The battery was disconnected for at least 1/2 hour....I had to make a repair to the negative battery cable/terminal....so it was at least a half hour......and since that reset, I have put close to 500 miles on it and the truck just keeps on running better and better. I cleaned the MAF sensor today and am in hopes that this will give a little extra mpg and horsepower. Everything that I read on it said it would...so we'll see I guess......

Hope this helps....

Thanx...Anita