Hello everyone,

Recently I have encountered a persistent P0121 error on my car which my scanner lists as an accelerator potentiometer out of range code and the car has very sluggish acceleration. I connected my foxwell and read that my max throttle angle at this point only opens to about 17% and it looks like my car is only going up 1 mile per second when I am flat out.

So far, I have replaced my gas pedal assembly, cleaned my MAF sensor and throttle body with no success. My next plan is to disconnect the battery for a little bit to reset the DME so I can recalibrate the pedal again. I will also look into my fusebox and see if there are any issues there or any loose relays as I was poking in there shortly before I had this issue.

Has anyone else seen an issue like this before? Sometimes it comes and goes when I restart my car but it has been more frequent as of recently. There are some times when the issue disappears for a time but just returns out of nowhere. I did look at the throttle angle position sensor and noticed that sometimes the throttle hits 100.3-101%. I don’t know if this is causing the issue or not but I don’t know if that reading is okay or not. Please help me.

 

In addition to the accelerator pedal potentiometer, there is another inside the throttle body. If you turn on the ignition without starting the car and wait about a minute, the DME will automatically calibrate the two potentiometers. You should hear the throttle actuation noise coming from the engine.

 

I hear it actuate once or twice as soon as it is in accessory for a little bit but it doesn’t flap as much as it used to. I am not sure what it does to calibrate the throttle body so I don’t know for certain if this is normal or not.