I'm going to go through this chronologically.

My car always pulled P0441 and P0400 codes. I traced the P0400 problem back to the EGR valve itself after some testing with a Mityvac and found that it wouldn't hold vacuum. After replacing the EGR my SES went off for about a week, even before addressing the second DTC. When the light returned, I double checked the EGR system and found nothing wrong (valve was down tight, solenoid was plugged in, vacuum harness was in correctly without leaks) and pulled the same 2 codes I started with. I then tried to mend the EVAP system causing the P0441. I noticed the vacuum line from the purge solenoid to the throttle body was rotted out at the elbow. Using a spark plug end and a small hose clamp, I fixed the line and reinstalled it, this time with a new solenoid (tb line up top). I waited a week and checked the codes only to find that I've pulled a third code, P1441 for excessive EVAP flow during non-purge.

What I'd like to know:

a. If I don't reset the DTC's with the battery terminal trick after supposedly solving an issue will the codes continue to trigger the SES light? That is, will a code live in the computer for a long period of time even after a problem has been fixed? (This doesn't solve the mystery of the SES-free week after replacing the EGR) Have I actually fixed the P0400 or was my car playing games with me?

b. It seems unlikely that my new purge solenoid is faulty so is there anything else that could be causing so much flow?

 

yes code will stay in the system for a few runs before it clears. check the evap canister to make sure its not coming apart or full of fuel.

 

I am not totally sure with our Camaros, but I had a Huyndai that stored certain codes in the computer until you cleared them.

 

I checked the new evap purge solenoid and it was stuck open... so it's either faulty or the char from the lines works fast.

I cleared the Ses codes but I'm still puzzled why it went off for a week after fixing the EGR valve...

 

if your getting coal in the lines then your canister is coming apart and need replaced. thats if you have not replaced already. if so you will need to clear the hose. was that you that changed your canister?

 

Nope, but I'm going to check out the lines tonight.

 

ok, there was another fellow that had the coal in his canister come apart on him and plugged the hose and solonoid with chunks of it. sounds like you have the same problem.