If anyone has a running count of my recent threads, you'll remember my 4Runner is running like crap. At the local, reputable, shop's suggestions, we tried the low buck fixes. Cap, rotor, plugs, wires, injector cleaner, all for naught to fix an intermittent miss.
After reading horror stories on Yotatech of people chasing the same issues, I bit the bullet and started to think it may be a bad sensor. I've done the throw parts at it till it works thing before. Berk that.
A link sent me to 4crawler's site. (Which I highly recommend for anyone rocking a 22RE truck.) I needed to test these sensors using a multimeter.
Oh God!
So I begin testing as per 4Crawler's instructions. The TPS test passed right down the center of the tolerances. On to the the air flow sensor.
It passed all the static tests. Damn. But once I moved on to the dynamic tests, I found my problem. The resistance when I moved the flapper door would go to infinity once I moved the door to any position. Not supposed to do that.
No wonder it ran bad. The ECU has no idea whats going on, so it went into a limp mode.
I've never had any success with electrons. They hate me, and I always feared a multimeter. They looked so intimidating.
Flush with success, I'm testing everything. No more parts throwing. 
t25torx
New Reader
5/14/13 3:44 p.m.
I <3 my multimeter. I was pissed off royally when mine was stolen out of my shed at night. I found a good one on ebay though to replace it with. It's very high on my prized possessions list.
If you and the electrons are on lousy terms, all the more reason to keep tabs on the little buggers 
I forgot to mention it was done on a free Harbor Freight meter. Sweet.
I remember way back when I got my first multy meter. I was a kid and I was testing everything including the voltage in the plugs in my house. And low and behold I got 145 Volts. I told my dad about this and since he had recently blown out several appliances, vacuum, and numerous other things he made a call to the electric company and told them of my discovery. They came in and tested and verified that the transformer on the poll out side my house was the problem and told my father to out together a list of appliances that had been replaced and submit it with recipes and they would send a check. My dad got reimbursed for about 2K in stuff he had replaced in the last 3-4 years since there was no way to prove when the transformer went bad. They also said that if any other electrical items go bad in the next year to file a claim. The electric washer and drier mysteriously went bad about a month later. (My dad never fessed up to that by the way) and the electric company paid up.
My $15 multi meter that I begged dad to by me for about a year ended up saving him a bindle of $$$$. After that he never hesitated purchasing me tools when I asked for them. I think he figured out that they were really "our" tools but he could tell my mom that he was getting them for me. LOL
Hal
Dork
5/14/13 6:35 p.m.
Appleseed wrote:
I forgot to mention it was done on a free Harbor Freight meter. Sweet.
I've got 2 of those - and 3 more higher quality ones. I keep one in my desk drawer, 2 in the shop in the basement and 2 in the garage. Can't live without a multimeter!
I've got 4 of the cheap/free ones scattered around my world, a Fluke auto ranging multi/amp meter in my tool bag for work, a event recording meter I can plug into my laptop, and a Fluke meter with a detachable display so I can check things remotely. I heart multimeters.
4crawler has a lot of good information and ideas on his site. Pay attention to what he shows about the knock sensor, how it is supposed to work, and how it generally doesn't work.
