sas'd22re

i have an 86 22re with a rebuilt motor. the motor has an rv cam, and oversized stainless steel valves. it sometimes has a rough idle...almost wants to die sometimes, has a slight hesitation and is getting horrible mileage. also, it smells like its running rich at idle. i replaced the o2 sensor last week and when i was on the highway since replacing it, i got a check engine light... code 5. when im driving between 2000-3000 rpms for a little while, the light comes on...if i hammer it or let off the gas it goes away immediately. so far ive replaced
plugs, cap and rotor
swapped in an IAC valve
adjusted the TPS
replaced the o2 sensor a week ago, still getting a code 5
checked my coil, the primary resistance was out so i swapped in my spare
checked the afm on the truck...didnt remove it and move the flap to see what it did
a friend did a fuel injestion flush and ran 2 bottles through

i have a spare but the numbers on the top are different
numbers on my afm are
22250-35020
197100-2470
my spares numbers are
22250-35060
197100-4070
will my spare even work? its from a 22re but the numbers dont jive
any help would be greatly appreciated

TOYOTA 1

code 5 is the oxygen sensor. you said you replaced it?

sas'd22re

yup, brand new

abecedarian

header?

sas'd22re

yes, it has a header. the o2 sensor was relocated just after the flange/ its a 3 wire heated sensor

abecedarian

so wiring is one signal and two heater wires or two sensor wires and one heater? ...
... is the heater circuit working?
... does the voltage on the signal wire oscillate when the sensor's warmed up?

sas'd22re

yes, one signal and two heater. i have not checked the voltage on the signal wire...how do i go about this?

abecedarian

using a high-impedance multimeter, measure the voltage between the signal wire and ground. when the sensor is warmed up, the voltage should swing between around about 0.1v and 1v.
you can google O2 sensor testing for more information

sas'd22re

ok cool. im gonna google that right now and check it first thing tomorrow morning. is there anything else it could be. the afm? as i said, i have a spare but am unsure if it will work

abecedarian

having a header lets the exhaust cool down a bit before it gets to the sensor, which makes it more difficult for the sensor to generate valid readings. a heated O2 helps though.
but without knowing whether the O2 is trending towards rich or lean makes it a little more difficult to determine what is failing.

sas'd22re

ok, thanks for the input. i have to wait til its light out to work on it, but i will post as soon as i do. please check back and let me know what you think

sas'd22re

edit, answered my own question.

sas'd22re

i unhooked the o2 sensor, connected my multimeter, started my truck (it was already warm) and looked at my readings. when i did not have it grounded it was reading .008 and when i grounded it it stayed around .400. i take it this means the o2 sensor isnt working properly, however, it is only a week old. what next?

sas'd22re

abe? anyone?