So my check engine light came on with the code p0505. So after going through the possible causes for the cel(cleaned the throttle body,replaced the iacv, double checked vac lines.) It popped back on. While I checked the vac lines I was curious and unplugged the iacv, and it idled fine. So now I'm stuck as what to do next. Can someone help me please, any help would greatly appreciated

Unplugged idles around 1000 rpms or so

Plugged idles between 1500-2000 rpms

 

Test the TPS and ECT sensor.

 

How do I test them and what results am I looking for?

 

Hook up a scan tool and slowly push the pedal down and watch for any uneven jumps in the percentage. According to the Helms you should be at less than 10% with the throttle closed and above 90% at WOT. Or take a multimeter and tap into the wires and have someone slowly push the pedal down and watch the voltage coming out of it.

Pretty much the same for the ECT. Use a scan tool to watch the temp or unplug it and hook a multimeter and watch for voltage jumps or no voltage. I want to say the high end should be around 5v for both and around 0v for bottom end.

My ECT is bad and you can see the temps jumps from 204 to 99 and then the car with stumble and pull timing.