Originally Posted by kleecker
I guess there is no set answer for how long a pending code stays there? .
Hmm.....if no pending codes.........you could look in the HISTORY location on your scanner if possibile............most inexpensive scanners don't have this capability though. Of the four scanners that I own, only one is capable of displaying Code History.
Something you could try when the idle is low is:
Hook up a scanner and look at the LIVE DATA......specifically, the TPS Monitor info. At idle, the TPS voltage reading should display 1 volt or slightly under. If voltage is 0.75 or less, chances are you have a defective TPS sensor. At idle TPS Percentage should display 11.4%
TPS is just a potentiometer........with a bunch of tiny electrical blades inside it. Various underhood temperatures can have an effect on thier operation when TPS start going bad.
Also, look at the ECT (engine coolant temperature) infomation with the scanner while the idle is low......a bad temp sensor could also have a bad effect on engine idle.