Ask Smokey! I repair my wife's pickup in the best Smokey Yunick moment of my life! (Using a vacuum cleaner)

As a wee lad I loved to read old magazines. Especially, Popular Mechanics and Popular science. My dad had a collection from the 30's through 50's and I read them all.
My favorite column was "Ask Smokey," where legendary mechanic Smokey Yunick would diagnose car problems though a masterful process of eliminating the obvious. The best ones were where two things were wrong at once but were unrelated and the answer turned out to be a crossed plug wire instead of a piston though the block. (don't confuse this with the Thanks Smokey! video on YouTube-totally different)
So....
Yesterday my wife called me and said her pickup was missing and backfiring and I might have to go rescue her. We just happen to have a truck with a roll-back bed at our disposal so I went to find the keys and warm it up.
By the time I answered three phone calls and loaded a pickup load of hay she had limped it back home.
Now here is the issue.
Last week the battery was dead. I doesn't want to hold a charge but it will change up when you drive the truck. The truck is a 2001 or so, F150 Ford with a fuel injected v-6. I avoid driving it as I'm afraid I will scratch it and because it has sensors and relays and computers and stuff I don't understand. Also, my father in law gave it to my wife as he was a little suspicious of my 1966 Ford.
The new battery arrived Wednesday and I installed it Thursday morning. When I started the truck after installing the battery the engine raced to full throttle. I shut it down immediately. I put the blame on the random workings of the computer. Who knows how those silly things work.
I started it again. Same thing. The third time I floored the accelerator briefly. I couldn't remember if there was an actual physical connection between the accelerator pedal and the butterfly valve on the fuel injection manifold but I gave it a couple pumps anyway.
The engine dropped in rpm but started making horrible clunking noises and backfiring, and then it cleaned out but ran like it was slightly out of time.
I decided that the computer had malfunctioned due to battery issues and started looking for the phone number of the friendly neighborhood mechanic.
But then, someone else came after hay.
Then my wife drove off in the truck.
I had a little time to come up with a plan while I waited for the family to arrive back home. I remember from Smokey's columns that engines have simple requirements. Fuel, spark, and air. Since I don't understand fuel injection or computerized ignitions systems I opted for an air check. Start simple, then confuse yourself later, is my theory on troubleshooting. Sort of like, if you can't shoot accurate then shoot often is my motto with guns. (if I had any) I meant NERF guns.
Wow, I get off topic really easily... did someone say cookies?
The Ford F150 has a really poorly designed canister type inline air filter. It is difficult to get the two halves of the canister seated correctly when you take it apart.
I took it apart and looked inside.
There had been a mouse nest inside. The truck is driven once a week or so and I would never have expected a mouse nest.

The mouse was gone and so was the nest. I suspect it was a traumatic exit. Perhaps it was the mouse who jammed up the throttle butterfly valve. Or perhaps it was not pinging but mouse screams that I heard when I started the truck.
But if the mouse nest is gone then why does the truck run funny?
I examined the intake tube. I saw wires. Wires must mean a sensor. So, there must be an air flow sensor in the intake tube.
And there was the problem.
A little bit of mouse nest on the airflow sensor.

I got the vacuum cleaner.
Now the truck runs fine. I am waiting for CarQuest to bring me a new air filter. Our local autoparts store delivers. It could have something to do with having so many leaky old tractors that we buy hydraulic fluid in bulk.
If any of my gentle readers wish to make a contribution to the Budd E. Shepherd auto restoration library they could buy me, "The Best Damn Garage in Town," by Smokey Yunick. I would love to have that book but it costs more than my budget. Or you could buy it for yourself though my Amazon search at the top of the page and I would get a small cut. If 500 people bought the book through the Lazy Farmer then I could buy my own. Or if one person bought 500 copies then perhaps I could borrow one of them. Or someone could give me that 1.2 million dollars and I could buy my own. Or someone just give me $5. I'd love to have an extra $5, or cookies, or pie, or even a kind word and a pat on the head.
Don't give me cheese. I don't really like cheese that much. Or eggs, we have lots of eggs.