How long until stored codes go away?

[havelegs]

I was driving yesterday and my car went into reduced power mode. The reason was the throttle body position sensor. I could usually tell when it's starting to go because at low throttle the response is very aggressive and jumpy.

I pulled the code yesterday to confirm but I had two:

P0606 ECM/PCM Processor << I would assume this one is trigged due to the TPS

P2135 Throttle / Pedal Position / Switch A/B Voltage Correlation

I replaced the throttle body with a stock one, mine was a little ported. The car runs fine, the MIL was still on but after about 15 miles and a few key cycles the MIL is off.

However, I still see the stored codes as above, but the light is now off.

Will it take more time before the codes clear from pending? I do not want to clear them with my device since it will reset the emissions status which can be a pain to get in.

There are no pending codes, so I am not sure if the stored codes are still valid or if they are just "stored".

Thanks