Need to diagnose my 93 pickup
12-26-2016, 04:27 PM
#1
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Need to diagnose my 93 pickup
I have a 93 toyota pickup 22re 2.4L 4x4. I just replaced my exhaust from the manifold back with a new cat and O2 sensor. I was hoping that would shut off my check engine light, but unfortunately not. After resetting the engine light it still remains on with the codes 21 heated O2 sensor front circuit 41 throttle position sensor circuit and 52 knock sensor circuit. So I know it can't be my O2 sensor since I just replaced it. The truck does run sluggish and often won't accelerate and bogs down. So I'm wondering where to start, it might be the wiring. Or the sensors could need replacing but if so why the 21 code? Any advice where to start or have a similar issue?! Anything would help. Thank you.
12-26-2016, 07:18 PM
#2
long shot... people have reported strange behavior when some of the electrical grounds are missing.
i can't remember 'em all, but i think that there is a ground wire from the back of the head to the cab, and another one hooked up on the intake manifold.
i would also look to make sure that the tps and the knock sensor are both plugged in.
i can't remember 'em all, but i think that there is a ground wire from the back of the head to the cab, and another one hooked up on the intake manifold.
i would also look to make sure that the tps and the knock sensor are both plugged in.
12-26-2016, 08:08 PM
#3
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Second on the grounds. It's doubtful that you would have all of those three things failing at the same time. I can't tell you exactly where all of your grounds are but look all around the fenders and the fire wall for a black wire without a home. As you find your grounds, check each of them and make sure you don't have a loose connection or anything like that. After that pull on them/wiggle them thoroughly and then reset your ecm to see if those codes are still there.
12-26-2016, 10:36 PM
#4
Change the EFI fuse, because it's cheap and could be partially blown. Look under the plenum and throttle body there is the primary ECU ground make sure you can't rotate it on the stud. Now inspect the oxygen sensor wires for cracks and scorch marks, it runs up over the transmission on gen 2 and tends to fail there. If you don't find anything obvious you need to take off the passenger kick panel and access the ECU wiring.
Someone else will maybe provide the ECU pin outs?
Insert one end of the continuity probe on the "ox" pin, unplug the sensor under the car and probe the line. It should turn up a short-circuit, if not shake the wire around. If you still can not find a short somewhere in the o2 wires I will be surprised.
Someone else will maybe provide the ECU pin outs?
Insert one end of the continuity probe on the "ox" pin, unplug the sensor under the car and probe the line. It should turn up a short-circuit, if not shake the wire around. If you still can not find a short somewhere in the o2 wires I will be surprised.
