'04 with 2.7L - step on gas, goes nowhere

Okay - my mother-in-law's boyfriend has an '04 PreRunner DC with the 2.7l and automatic, less than 100,000 miles. For months he had an off-and-on hesitation problem which eventually set a code for what he calls the "manifold sensor" (I think he means the oxygen sensor, since he bought a Bosch to replace it).

Anyway, he was stuck in traffic the other day behind an accident, and put the thing in park. Once traffic started moving again, he put it in drive, put his foot on the accelerator, and... nothing. It just sat there and idled, and went nowhere. He said that eventually, after hitting the accelerator several times, it finally started moving, and was okay after that. He took it to the dealer to have them check it out. Of course they couldn't duplicate it. He also called the Toyota care line, and they couldn't help him.

So I'm open to ideas. I'm thinking maybe it was the MAF sensor (not picking up the change in airflow), or something else. He first thought transmission, but if it wasn't coming off idle, that's probably not it.

The thing is, he doesn't know if it'll happen again tomorrow, or not for another six months. Thanks in advance for any suggestions.

 

He needs an obd2 scanner to pull codes.
Most likely it's those Bosch AFR sensors.
He will need Toyota AFR sensors.

 

04 uses a throttle cable check that. But in all honesty it sounds like he got distracted then panicked and thought he was on the throttle but might of hit the brake... tons of accidents happen when people put their vehicle in park during traffic/redlights for this exact reason. It's dangerous and unnecessary... tell him to leave the vehicle in drive when driving that way if it ever happens again switching from park to drive at least he's in a drive way or lot.