I have a 04' with the 5.4 in it. It is time for emissions testing and the first test was a fail due to readiness. The workers told me to put a few hundred miles on it, so I did. Went back and the truck was still not ready, even after putting over 500 miles on the truck. The sensors not ready were o2, o2 heater, and cats. There are no codes being pulled and each of those sensors have been replaced in the last year and a half as well as the PCM. Any ideas?

 

Same thing happened to me (04 XLT SCAB 5.4) because I had to replace the battery prior. Had to get onto the highway and put about 200 miles on it in one trip.
If you’re just driving it around for shorter trips the cats and the sensors will never reset and come on line. You usually need to do 150-200 miles in one trip on the highway trying to remaining at a constant speed.

 

I had put about 300 miles, mostly shorter trips. After failing again, I drove roughly 250 miles and had my computer plugged in the whole time and only a couple o2 and cat sensors did not come online, or they were in and out. The same after a 300 mile trip I just did, so driving it to try to reset the codes sadly isn't going to help now.

 

I was hoping that it was that simple for you, because I know how aggravated I was with it. I hope someone has an answer?

 

Did you go with oem sensors? Not sure about Ford's, but had a bad o2 sensor on my hatch and it didn't like off brand.
Just a theory.

 

I'd have to check and see. Had all of the sensors replaced solely because of emissions previously.

 

Read up on a complete drive cycle...

 

Went through the drive cycle and completed it twice, still nothing with those sensors. That was pretty much all I was trying to do after failing emissions the second time.

 

What is the specific "drive cycle" you did?

 

I mentioned this issue to a someone I know who does inspections here in MA. He’s seen the issue frequently and recommend that you check your battery?
It could be caused by a weak battery? He’s seen it even when the battery has been replaced, but found to be defective when tested.