99 ford ranger losing power

truck started running rough…i replaced the plugs, plug wires…still rough…i changed the maf sensor and th iat sensor…but still loss of power , acts like not running on all cylinders

Have you checked for any error codes. Sometimes you will find them there even if the CEL is not illuminated.

Did you replace the MAF with no more reason than it is running rough, or is there something else we might need to know? 

How old are the air and fuel filters.

How many miles on your Ranger?