Toyota Repair: problems with 91 4runner 22re when it warms up, oil pressure switch, oxygen sensor

Question
QUESTION: When my 91 4runner 22re warms up I have (has to be good and
warm) it acts really weird and the check engine light comes
on.  I checked the codes and I get a 5 and 2.  What happens
with the engine is that it idles really low and it has no
power.  If I cool the engine down and restart it works
until it get warm again.  I have swapped out the AFM with a
doner, no luck.  Any ideas?

ANSWER: I think what you have is a trouble code 25 which would indicate a bad oxygen sensor, the one in front of the cat converter.

---------- FOLLOW-UP ----------

QUESTION: why do you think that?  I get 5 blinks, then 2 blinks (pause inbetween).  I do not get the 2 blinks first.  Do you still think it is a bad sensor?  Code 5 is pointing to a circuit break of some sort to the sensor.

Answer
If there is a code 52 there is a problem with the engine knock sensor, it may not be connected or it's malfunctioning, the knock sensor should be located on the left side of the engine block, it looks kind of like an oil pressure switch, it has a single wire connector, the code could also be set because of overadvanced timing which can cause pre-ignition or engine pinging,if that happens the computer will retard the engine timing to compensate and reduce the pinging,this will cause a loss of power until the engine cools off or the sensor stops getting the pinging condition, another cause could be that the engine is running hotter than normal which will have the same effect,this may explain why the problem is temperature related.