Where can I locate the number 3 cylinder on a 2004 Ford Freestar 3.9L?

The 2004 Ford Freestar SEL is equipped with a V6 engine, and it typically has two heated oxygen sensors (HO2S) due to its dual exhaust system. These sensors are also commonly referred to as oxygen sensors or O2 sensors. The specific details may vary depending on the exact engine and exhaust configuration of your vehicle.

1. Bank 1 Sensor 1 (B1S1): This is the upstream oxygen sensor located before the catalytic converter on the side of the engine where cylinder 1 is located. It monitors the oxygen content in the exhaust gases before they enter the catalytic converter.
2. Bank 2 Sensor 1 (B2S1): This is the upstream oxygen sensor located before the catalytic converter on the side of the engine where cylinder 2 is located. Similar to B1S1, it monitors the oxygen content in the exhaust gases before they reach the catalytic converter.

These sensors play a crucial role in monitoring the air-fuel mixture and helping the engine control module (ECM) adjust fuel delivery for optimal performance and emissions.
Please note that vehicle specifications can vary, and it's always best to refer to your vehicle's owner's manual or consult with a qualified mechanic to get accurate and specific information about the number and location of oxygen sensors in your particular 2004 Ford Freestar SEL.

1 4 2 3 5 6 is correct

https://www.fixya.com/cars/t9279341-firing_order

More here

https://www.google.com/search?q=2004+Ford+Freestar+4.2+engine+V6+firing+order&rlz=1C1QJDB_enCA643CA644&sxsrf=ALiCzsZKJXqt9yxHd7ROQEGo5Z6XxAX2_w:1667065837273&source=lnms&tbm=isch&sa=X&ved=2ahUKEwi2wLCYgIb7AhW9m4kEHVSfCy4Q_AUoAXoECAEQAw&biw=1920&bih=937&dpr=1

..

The firing order should be, 1 4 2 5 3 6.
Ford numbers their cylinders in numerical order.
Passenger side bank, front to back, 1 2 3
Driver side bank, front to back, 4 5 6.

There is 4 senors the bank 1 sensor 1 is located in front of the LH (Drivers side) catalytic converter
Hope this helps

The spark plug firing order is ( 1 - 4 - 2 - 5 - 3 - 6 )

The engine cylinders are 1 , 2 , 3 from front to rear on the passenger side of the engine and 4 , 5 , 6 from front to rear on the drivers side of the engine

The coil pack towers are numbered 1 , 2 , 3 from front to rear in the row nearest the passenger side and 5 , 6 , 4 from front to rear in the row nearest the drivers side

hope this clarifies the situation for you

Please watch the Youtube video at the link provided. Spark plug replacement Ford Freestar 2004 2007 V6 3 9L Tune up Install...

o2sensors are located in the exhaust system.you have 4 o2sensors on your car.so you need to know which sensor your looking for.bank 1 sensor 1 is the first sensor in the exhaust pipe on the side cylinder 1 is on.bank 2 is on the side cylinder 2 is on.then you have a sensor before the catalytic convertor and one after the convertor.

On Ford engines, #5 cylinder is located between #4 cylinder and #6 cylinder (see picture) Please note that the arrow in the picture is pointing toward the fornt of the engine, NOT the front of the vehicle. With this in mind, the picture is accurate for both front wheel drive vehicles and rear wheel drive vehicles.

STANDING FRONT OF VECHICLE CYLINDERS FACING YOU ARE 4 5 6 AND BACK CYLINDERS IS 1 2 3 NOW ON PIECE PAPER LOOKING AT IGNITION COIL PACK FACING YOU WRITE BACK NUMBERS 123 AND UNDER THAT NUMBER 1 2 3 WRITE FRONT NUMBERS 5 6 4 THATS YOUR COIL PACK PLUG WIRES LOCATION. LIKE I SAY 5 6 4 IS PLUGS WIRES LOCATION FACING YOU AND BACK NUMBERS 1 2 3 PLUG WIRES LOCATION ON COIL PACK. FIRING ORDER IS 1 4 2 5 3 6

in the back #1 first from pass side