Very possible the throttle body gear is damaged, replace the throttle body, do a battery lobotomy, and let us know.

 

They all read bad connection to me except maybe p0171, but that is because the MAP.

Notice they are all in the same area of the harness.

 

I was wondering about that, donbrew. I checked the wiring that I saw in the picture from the link you provided about the P2135 code. I didn't see anywhere on any part of any wiring that could chaff on the EVAP bracket. I attached a picture of my wiring harnesses and the EVAP bracket.

Can you give me an exact location of where all those connections come together in the harness?

 

The connector at the ECM.

 

Here

 

It's been several days and a couple hundred miles with no engine codes or Reduced Power messages (both highway and city driving). If there was a problem with the gears in the throttle body, wouldn't it be more of a constant issue? If it's in the wiring or connectors, would I be able to locate or isolate the problem by wiggling the harnesses around while the engine is running?

 

You might, you might.

 

The muffler came off. After that, there was this

 

All pending faults, try a battery lobotomy, then have your battery load tested.

 

My guess is more than just the muffler came off, more likely a large part of the exhaust upto the catalytic converter. And you may have blown a fuse or 2 (the one labelled "emissions")