i ran codes on my 1995 f150 and go a 121 code i found that this code means closed throttle voltage higher or lower than expected, any ideas and what code be wrong

 

Likely an issue with the TPS sensor on the bottom of the throttle body. Could be a few other things, which you might try first - I would try cleaning the throttle body with throttle body cleaner, and what's the idle rpm? A previous owner could have adjusted the throttle stop and gotten things screwed up.

 

its ideling at right under 1000 rpms

 

Hmmm... that's probably about right - does it drop to 600-700 in gear?

Either way - I'd predict a TPS replacement in your future.

 

i will try cleaning the throttle body and run codes again, if that doesnt work i will have to invest in the TPS sensor and change it. thanks for your help

 

how hard is it to change the TPS sensor 1995 f150 5.0. i see two screw under the throttle body but there is very little room to work. any suggestions

 

i know your trucks a 95 but this is the how to on checking the tps voltage.
for a newer model. this might help you tho.
i'm pretty sure you just disconnect the wires and undo the 2 screws and put the new one in place. then follow the instructions for adjusting the new tps
http://www.f150online.com/forums/lig...ttle-body.html

 

You have to remove the throttle body to get the TPS off.

 

Yeah I have some pictures posted on my profile if you wana look how i did mine, not sure if they are different. Its pretty straight forward after you remove everything.

 

thank you the pictures helped. i will get to it tomorrow and take care of it