Whoops! Tried to pull CEL - shorted wrong pins!
 

:bang:
1994 4Runner 3VZE 6 cyl.
Previous codes :
2, 5, 71
I just replaced my O2 sensor and was taking it for a spin. Nice, no CEL on startup, its only when shifted into drive. Much more responsive during acceleration. Cool.
Now back home I was curious what code this would be now. I was going to pull up a diag pinout, but my phone was dead and thought I had done this enough times to remember. If I remember correctly, I jumped B+ and Te1. Realized I jumped this incorrectly and removed the paper clip.
Now it starts up but cuts out/bogs in a second. I ran the code correctly this time :prop: and counted 24.
I have already checked all the easily accessible fuses which all appeared to be intact. (Driver side kick board and by the diag port)
Any recommendations on how and where to start troubleshooting?

Did you do any work on/or near the VAFM?
I would just make sure it working properly also, check connections, check specs.

How did you check the fuses? You need to put a meter on them to make sure they are good, they might look ok but there're not
Welcome :wave:

1. If you jumpered B+ (batt) to TE1 (gnd) you would have blown the EFI (MFI) fuse. http://personal.utulsa.edu/~nathan-b.../2powersou.pdf But then you'd have no spark, and it wouldn't run at all.

2. Code 24 is loss of signal from the intake air temp sensor, which is in the VAF. That's why ksti asked that question; if you have the VAF unplugged it will throw that code, AND it will start, run a few seconds, then die. This is because another part of the VAF connection is the FC (fuel control) switch.

3. I doubt you have a blown fuse, but NYHumpin gives good advice. Use your multimeter, and you'll always be sure.

4. To track down code 24 and your start-then-die issue, jumper B+ to FP. This forces the fuel pump to run. If the engine runs now, you have a problem in the VAF COR circuit.

5. FWIW, you did NOT have code 2 or 5. Probably code 25. http://web.archive.org/web/201211190...85diagnosi.pdf

TE1 is actually the test pin, not ground. E1 is the associated ground to the ECU. TE1 is an input directly to the ECU board, so by connecting it to B+ you put +12V directly into the ECU, which is primarily a 5 volt system. Not the best of things to do, but I would be very surprised if Toyota didn't provide resistors and clamping diodes as protection on all of those diag port lines, anticipating exactly that sort of mistake. Certainly at HP/Agilent/Keysight, or at any other first echelon electronics company, we would have done so.

So, my guess is you did no harm with your misplaced paperclip, but somehow, as has been said, interrupted the VAF circuit as another part of your troubleshooting process.

Doh! RJR is correct.