sensors on renix

i just checked a couple sensors on my 88' 4.0 renix and the tps was out of adjustment by about 10%, also the manifold air temp sensor and the o2 sensor are bad. once i replace these two sensors and adjust the tps will that make a big difference in my jeeps performance/gas mileage. because right now it is very underpowered and has bad fuel economy so i'm hoping this will help.

Yes those sensors if bad will create a poorly running and poor gas milage motor. So if they are bad replacing them will help. Here is a link to a helpful page on the Renix sensors
http://www.lunghd.com/Tech_Articles/Engine/Basic_Sensors_Diagnostics.htm
As far as bad milage what are you considering bad?

sorry, i was away on business all week but yeah, i'm getting about 14mpg with my 88' xj lifted 3" and 31" bfg A/T's.