My ailing Dakota

[patsfanme14]

Hey guys and thanks Fred for the response and letting me know to post a thread to get better responses...lol. Well heres the deal I have a couple issues with my recently acquired Dodge Dakota.
Its a 1998 3.9 automatic with 110,000 miles on it. Got a couple issues with it and trying to get road ready. The story is the vehicle has been sitting for about a year and a half. The vehicle starts and has a erradic idle also the strange thing is that the speedo flucuates as if its a tach as you step on the gas.
Also as fred knows about there is a code P720 that I am pulling from my OBD2 scaner. I replaced the low output sensor on the left side of the tranny and the code is still there.. Question is I heard there is also another sensor (which I believe I saw) on the Tranny could this one be faulty too? And if so why is the code the same coming up if it is. Upon acceleration the truck seems to be lacking power.
Well I will start with these concerns, and add as we resolve them so any help you guys can give me will be greatly appreciated. And Thanks in advance...Craig

[2000izusu]

the code will still be their if you didn't reset after the sensor replacement. did you reset after sensor replacement?

also is you throttle body clean? especially the iac.

[jmroot]

check the wires they run over the top of the tranny from the other side and could be a problem if sitting. Mine overheated and melted from the o2 sensor amd gave problems with 4th and lockup.