okay, driving around today, SES light pops up, I auto tap it and this is what I see:

Daignostic Trouble Codes
P1121 TP Sensor Circuit Intermittent High Voltage
P0123 TP Sensor Circuit High Voltage

Pending Daignostic Trouble Codes
P0123 TP Sensor Circuit High Voltage.


JUST TELL ME HOW TO FIX THIS PLEASE!! RACEDAY IS TOMORROW, I just switched TB's(MMMS p orted one about two weeks ago) please Help! DO I NEED TO GO TO THE DEALERSHIP AND GET A PART?????


Thanks!

 

FYI that sensor is like $40.

Check to make sure everything is plugged in right. Sure you don't have an odd air leak or something?

When TPS sensors go bad, in some cases you will floor the car and the car has like 25% of normal power. Problem can be intermittent too.

 

Has it been doing this since you did the throttle body (and not before)? My money would be on a loose connection or broken wire if so.

I'm ignorant about F-bodys... the F-body doesn't use the same throttle control as the Y-body, right? (The 98 Y-bodys have a TSB out on the TAC/TCM that has symptoms a little like this.)

 

If I'm reading this right, you just changed out the throttle body?

I'm more familiar with Tech 2, but I would assume that Autotap gives you data as well. There should be something that represents TP voltage in the data stream. According to the info I have at hand, the PCM will set the P0123 if the TP voltage goes above 4.75 volts for 10 seconds. It sets P1121 if it sees above 4.80 volts for 1 second during a 20 second period. Sounds like you may have the TP either mis-positioned or misadjusted. With a throttle body that has been worked, you may have to elongate the holes on the TP sensor to make it adjustable. Basically, you'll need to adjust it so that you don't get more than 4.75 volts at WOT.

 

PSJ: It DOES SEEM like im having less power. FYI
on the 2-3 pull, the car seems to lag a lil
bit, is this what your talking about? It
just seems that the car does NOT pull as
hard under WOT


ToplessTexan: this NEVER happened when i had my
stock TB.I checked the hoses and
wires and everything looks secure


Riptide: you bring up a good point. I will autotap
it right now and see where my volts are
at.

thanks everyone for your help, i'll let you know if my cars acceleration gets back to normal

 

Update: guys i went out tonight and put on my original TB and the problem WENT AWAY!!!!!!!!!!!!!!!! PHEWWWWWWWWWW!!!!!! I want to thank everyone that helped me out. Pro STock john, it seems as if my power has been "fully restored"
Thanks!!!!!!!

 

[quote]Originally posted by SSBoy:
<strong>PSJ: It DOES SEEM like im having less power. FYI
on the 2-3 pull, the car seems to lag a lil
bit, is this what your talking about? It
just seems that the car does NOT pull as
hard under WOT
</strong><hr></blockquote>

SSBoy, I think the reduced engine power PSJ is talking about is the 'limp home' mode. It's not a small loss of power, it's 'can barely get out of your own way' power. Failures in the electronic throttle control (typically some sort of disagreement among sensors) in the C5 triggers this. I don't think your power loss sounds this severe. I think Riptide is pointing you in the right direction with the adjustment of of the sensor on the new TB.