One
motorcraft . com just shows ( 1 ) oxygen sensor for all available engines in a 1991 Ford Ranger
yes it has both. at least in my 1991 ford ranger does
Look by the balancer.
the o2 sensor is located on the exaust manifold
I don't know if it is the same as the Ford Mustang , but the BAP sensor was mounted on the firewall - good luck
If your looking for the oil level sensor it would be located on the driver side on the oil pan.
If it's like a 1991 Ford Explorer ( with the 4.0 liter V6 engine ) It has ( 1 ) oxygen sensor
Where is the ford ranger 2004 revcounter sensor conected
Yes , a 1991 Ford Ranger has engines that are fuel injected
Location fuse box on 1991 ford ranger
No
Looking at the 1991 Ford Ranger - 4.0 L V6 - engine wiring schematic in my Chilton repair manual , it shows ( ONE ) heated exhaust gas oxygen sensor