94 K1500 5.7 - Can’t Figure Out Code 43!

[19Silverado94]

I can’t for the life of me figure out this Code 43. Comes on a few seconds after start up. I’m getting 4.94V at the connector with the KS unplugged. What else is there to check? Thanks in advance for any help. The parts below are new.

PCM Computer
Distributor
Cap and Rotor
Spark Plugs and Wires
Ignition Control Module
Knock Sensor
Engine Temp Sensor
Engine Temp Sender
Throttle Position Sensor
Idle Air Control Valve
Manifold Absolute Pressure Sensor
PCV Valve
Fuel Pump and Filter
Fuel Injectors

I read somewhere that there are 2 different ohm readings for sensors? How do I check this?

 

[c1500deathtrap]

would it by chance be a bosch 02 sensor?

 

[19Silverado94]

would it by chance be a bosch 02 sensor?

I have no idea? I looked underneath and see it’s got 3 wires on it.

Also found this at the front of my wiring harness. What is this supposed to be?

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Some kind of connector that’s been jumped by a piece of wire.

Update: O2 sensor appears to be factory. Whatever was OEM.

 

[19Silverado94]

O2 sensor not it. My Sgt. is a mechanic and gave this to me while we were discussing the issue one night. Figure I’d pass this along for anyone else who may find this useful.

You must be registered for see images attach

 

[Jeffro87]

Corroded knock sensor wire? Need a pigtail maybe? Are there two ks on this truck?

The jumped plug looks like a pressure switch for a/c.

 

[19Silverado94]

Corroded knock sensor wire? Need a pigtail maybe? Are there two ks on this truck?

The jumped plug looks like a pressure switch for a/c.

I will order the Knock Sensor connector later today. I’m going to also probe the wire after the connector and see there’s a difference in voltage.

 

[Jeffro87]

I know those old single pins used to collapse, corrode or fall apart.

 

[19Silverado94]

10-4, I’ll try it. Only $4 on RockAuto.

 

[bradros87]

I have no idea? I looked underneath and see it’s got 3 wires on it.

Also found this at the front of my wiring harness. What is this supposed to be?

You must be registered for see images attach

Some kind of connector that’s been jumped by a piece of wire.

Update: O2 sensor appears to be factory. Whatever was OEM.

Did you find out what that plug was for? Mine has the same

 

[scott2093]

Did you find out what that plug was for? Mine has the same

looks like an AC pressure switch connector.. Not good if someone just jumped it and left it that way. Usually some do that to determine if switch itself is bad