01 Grand engine wiring question

[classy_gene]

I recently acquired a 01 Grand that the motor was already taken out. I have put another motor in it buy can not figure out where two of the plugs go! They are both 4 pin yellow square plugs on drivers side. One on top of the intake behind the air intake and the other one drivers side at front of engine. Pics attached, Thanks!!

 

[paradineai]

They are o2 sensor plugs. The 99-04 i6 motor has 2 more o2 sensors on the exhaust manifold. The manifold has 2 pre-catalytic converter units built in as well. The reason for this is because jeep also reduced the size of the exhaust ports on the heads to help the engine/precat/o2sensor system to warm up faster.

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[classy_gene]

They are o2 sensor plugs. The 99-04 i6 motor has 2 more o2 sensors on the exhaust manifold. The manifold has 2 pre-catalytic converter units built in as well. The reason for this is because jeep also reduced the size of the exhaust ports on the heads to help the engine/precat/o2sensor system to warm up faster.

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Thanks! I figured what the connections were for. I guess that is what I get for working on it after being held over at work all night.

 

[paradineai]

Now try swapping an engine, transmission, and transfer case all in under 4 hours without a lift or hoist.

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