I live in CA where my 2002 Saturn passed a smog test in March of this year. I put less than 100 miles on it between then and November, when I wanted to sell it. I smogged it again at the request of a potential buyer and it failed due to a service fault code. The code was a manufacturer specific P040 - EGR “A” Control Circuit Range/Performance. It’s probably related to it needing an oil change but can’t be sure without having someone look closer at it. The car otherwise runs great; no functional or operational issues to speak of. I have a very, very limited amount of money to spend on this. I was selling it because I need money so this is obviously not what I wanted to hear.
My question is this: The check engine light occasionally comes on but goes away within a day or sometimes within minutes. When I got the smog test the check engine light was on, which was a big mistake on my part. I’m thinking that it would have passed had the check engine light not been on at the time since code may not have been “firing”. I’m thinking of not even taking it to a mechanic and just going right back to the smog shop when the light is not on and see if it passes. I spoke with a mechanic over the phone at a different auto/shop shop who thinks it could pass and I should give it a shot. He was most worried about the light coming back on during the test, but it doesn’t usually fluctuate that quickly. I only have one free re-test though so I wanted to get some other opinions. Is anyone familiar with how these service fault codes work that can give me a good guess of whether or not the code would come up again if I re-tested it at a time when the check engine light was not on?