Intermittent and Sudden Power Loss/ABS & Airbag Lights and P2238 Code

2004 Tacoma 3.4l 5speed 4x4...sorry for the long post but trying to be thorough here about a weird issue that happened with my truck today.

Today I was on a rough trail, a lot of water and mud from recent snow melt. After a couple hours of running around the trail I noticed my truck would intermittently and suddenly lose power as though it wanted to stall while I was accelerating, only when it was bouncing around (won't happen when driving straight on a smooth section). While this was happening I could hear what sounded like an electrical "zap" or arcing coming from the engine bay.

Whenever this intermittent power loss would happen, my airbag light and ABS lights would flash on the dash and the RPM gauge would suddenly drop to 0 (even though the engine was still running). It felt as though the truck lost all power for a second or two, and then would go back to normal, as long as I kept my foot on the gas. If I let my foot off it would stall.


Pulled over the first few times this happened and couldn't see anything wrong visually in the engine bay. Air filter is dry and clean (have a snorkel), my first thought was maybe a fuse or something got wet that shouldn't have. After about an hour of this, a check engine light came on and I used my OBDII scanner which showed a P2238 code, for the upstream air/fuel sensor I believe.

Should I look into replacing this sensor? It seems odd to me that my truck would be stalling itself and making electrical arcing noises related to a bad air/fuel sensor.

Most of my searching on the P2238 code doesn't bring up anything about sudden power loss/flashing dash lights. Anyone experience something like this before? On the 2 hour long freeway drive home, the truck behaved normally (minus the CEL which I cleared twice and it would come right back seconds later). Symptoms only present themselves when the truck gets bounced around.

Hoping I'm not looking at an electrical issue because I'm pretty clueless when it comes to figuring those out, but if anyone has any experience with this I'd appreciate any advice you could give. Thanks in advance

 

Update - so I took a closer look under the hood this morning in the daylight and noticed almost right away that the metal hold-down bracket for my battery had been making contact with my battery's positive terminal...which explains just about everything. The corner of the bracket was melted and burned pretty good.

Everytime I hit a hard enough bump or made a hard enough turn, the battery would move just enough to make contact with the bracket and would cause a temporary short that triggered the symptoms I was getting (sudden power loss, dash lights, etc.).

The CEL for the P2238 code went away on it's own and hasn't come back yet, though it still shows up as a stored code on my OBDII scanner. Hopefully after the ECU completes a few emissions cycles it will go away, I'm hoping the constant shorts triggered the code and didn't actually harm the sensor...time will tell.

 

Time to get a hold down from @Coupe