Mass airflow sensor

[72nova]

My service engine light came on in my f150. Scanner said it was maf. I changed it out tonight and now it idle really rough. I drove it around a few miles and still doing it. How long does it take for the computer to learn, or is there something else i should be looking at?

[MrQuick]

depending on the year there should be a drive cycle relearn procedure. If not driven a specific way it could take weeks or days.

BTW, what was the MAF code exactly? Was it a voltage code? Could be a faulty connector too. List the code and your year, might be easier to get assistance.

[72nova]

It is a 2000. As far as the code, i dont know, autozone scanned it.

[MonzaRacer]

First mistake, a parts store scanned it. USED to be that (when Iworked for 'Zone) we had to print out code parameters and tests/procedures.
You might have a vacuum leak, if its 4.6 there are vacuum boots that leak and cause codes.
Fords also never reset baro reading unless you clear computer(disconnect battery, wire cables together for few minutes to drain all capacitors, etc)oh and remember negative should be taken off first or you can damabe electronics.
Too bad your noat around my area I could scan it for you and point you in right direction. Honestly if you want to diag an OBD2 car, get a reasonably priced scanner from ebay or even one of the more pricey 'Zone scanners. IE one that actually reads PID(parameter IDs) so you can read what each sensor does. On Fords Baro reading NEEDs tho be above 156, 157-158 is much better for cars at sea level.
Also watch short term and long term percentages, they will got from positive to negative, added together or subtracted (ie +3 and -3 =0) should come up to + or - 10, also your primary or front O2 sensors should range from below 200mv and above 800mv, THESE parameters tell you the computer is in control of the engine.
One better bottom end scanner that give two PIDS at time is Snap On/Blue Point Microscan (http://www.ebay.com/itm/Blue-Point-M..._Tools&vxp=mtr or http://www.ebay.com/itm/Snap-Diagnos..._Tools&vxp=mtr
These units run $399 if I remember correctly and you can buy the adapters for older OBD1 FI stuff too making it more useful.
May not have all bells and whistles but I was thinking of getting one, or go look up an Ethos, its little more advanced.
good Luck and get us some info, might be able to help.

[72nova]

Lee you hit the nail on the head. Had 2 leaks, one was a 90 degree boot right under the throttle body. I had to take it to local shop today, he hooked the smoke machine up to it and found them. I learned a lesson not to go by what autozone scanner says. Thank you and mrquick for the help. Lee your probably not that far from me, im in louisville.

[MrQuick]

no problem, glad you got it fixed, yeah lee's ok....once you get past all the babbeling. LOL j/k lee.

[MonzaRacer]

Gee Mr. Quick, thanks. Yeah figured the elbow, maybe some other vacuum lines. Swapping parts,,,,,if you own them too swap out, fine, buying them,,,strategy based diagnosis works MUCH better and CHEAPER!
Good luck, hope it doesnt have MORE issues.