Car has set a code 21 which is tps voltage (high). How do I fix this code. Recent additions to the car are new holley 58mm tb, and a tps switch for the nx kit. What should I start looking for to fix this?

Joe

 

The PCM is seeing a closed throttle TPS value higher than 0.90V. There's a good chance the throttle blades on your 58mm TB aren't closing all the way (did you adjust idle using the throttle stop screw?), or that you didn't index the TPS sensor correctly to the end of the shaft.... or that your TPS sensor will need to have the screw holes slotted so it can be rotated slightly to accomodate the design of the TB.

Start by checking the TPS voltage between the blue signal wire and the black ground. Should get a closed throttle voltage in the range of 0.20-0.90V (something closer to 0.5-0.67 is probably "preferred"). The WOT voltage should read approx 4.0V higher than the closed voltage, and the voltage should increase smoothly as you rotate the blades from closed to full open.

Did you check the idle speed, IAC counts and TPS voltage when you installed the 58mm TB? That is usually a good idea.