I was told that pulling the fuse to the car's computer or simply disconnecting the battery will wipe the computer's fault memory and clear any current faults that were showing. My question is: If this is done to clear a P0440 EVAP code, and whatever was causing the code has not been repaired, how long would it then take to go active and illuminate the SERVICE ENGINE SOON light again?

 

Not exactly sure as it varies, but if it wasn't fixed, it WILL come back

 

When it detects the fault again! Usually in a couple drive cycles

 

What do you mean by drive cycle? Someone told me that it could take up to 20 key turns or 60 miles of driving

 

It really does vary. My primary O2’s are DC’d, and sometimes the light will come back the next key turn, sometimes not for up to 300 miles, (up to 6x key turns). Just fix the problem.

 

And, no, it will never pass emissions

I guess you could fool a buyer.

 

They did...and I got fooled. Now I'm just pissed and want to try an prove that that is what he did to misrepresent the vehicle.

 

Ouch, private seller or dealer?

 

private seller...fracking kid...was cool to begin with, then clammed up and claimed "as is" Karma will be a ***** for him.

 

Evap codes aren't a big deal. This can be a gas cap or crack in the charcoal canister/hose. Get under it and inspect it.

 

That's pretty much the best type code to have IMO. Even if it's FUBAR'd under the car, easy and cheap fix.