'01 F-150 OBDII question...
 

After resetting a trouble code how long should it take for all of the system monitors to reset? The catalyst and evap monitors have not reset after 150+ miles of driving with at least a 3/4 tank of gas. My truck will not pass the scanner test for NY state inspection until one more monitor is set. The code I erased on Friday has not come back.

That's hard to say - depends on the weather and how you drive.

For the EVAP monitor to run the fuel tank must be > quarter tank and < three quarter tank, a six hour cold soak, and the ambient temp (infered from the IAT) between 40* and 100*.)

For the Cat monitor to run the vehicle needs to be driven at a steady state speed between 1000-1200 rpm, 1200-1500 rpm, and 1000-1600 rpm, with coolant temp above 170*, IAT above 20*, and no EGR faults.

(Since NYS allows one monitor incomplete on a 2001, if you have a known EVAP fault, keep the fuel tank above 3/4 to keep the EVAP monitor from running, forcing the Cat Monitor to run, and then getting it inspected.):-X22

My OBD scan tool has a Live Data function. What functions should I be looking at for optimal range for the catalyst monitor? Plus, what is IAT?

How many miles need to be driven between each RPM range usually? Is it hard to determine? 200 miles now and still no luck. The temp during the day has been between 35*- 45*F.

The PCM diagnostics does not depend on how far you drive but the drive cycles you do for down time, cold starts, accelerations, decelerations and steady speed intervals etc.
If the PIDs are still being worked on and no codes are set due to failure they are not done being tested.
Good luck.
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Intake Air Temp sensor.

(If it is wayout of range it could cause some monitors to not run.)

Everything was reset on Friday and I now have around 225 miles on it. At what point should I start to be concerned of an underlying problem. I ran into a similar problem two years ago when my truck would not pass emissions because a certain monitor would not run (can't remember which). I could not figure it out and another garage couldn't either. I resulted in going to the Ford dealer stealer. They found it to be a faulty thermostat that was making the truck run only one degree below normal, and it was not allowing the computer to cycle because of the problem. It took them a week of swapping parts and calling the Ford engineers in Dearborn, but they found the problem. And it only cost me $800.:'(

I'm just afraid of another scenario of it being something I can fix, but only not knowing how to diagnose it first. I'm starting to wonder if the catalytic converter is bad. The truck now has 220,000 miles on it.

A week of "normal" driving is not uncommon.

Does your scan tool show engine coolant temp > 170*?

And IAT > 20* ?

..and, if it does graphing, look at the upper and lower O2 sensors and compare the switch ratios.

It finally did it! The catalyst monitor started running yesterday and I was able to get it inspected. What finally worked was driving to a long stretch of road with a speed limit of 35 mph with very few stops. I decided to try a slow and steady approach again keeping the RPM's at about 1200 and my speed around 40. After about 2 miles of doing this the catalyst monitor indicator on my scanner stopped blinking and turned on.

I want to thank everybody who replied to my thread. I was loosing hair over this. I guess the computer needed a certain driving style.

Yes it does. It's called Ford's "OBDII Drive Cycle" if done for diagnostic purposes.