intermittent not starting and is throwing a small EVAP code, P042 or P046?

2001 KIA SEPHIA
85,272 MILES • 1.8L • 4 CYL • 2WD • AUTOMATIC
Avatar
2001 KIA SEPHIA
  • MEMBER
  • 4 POSTS
I usually have a problem starting it after driving short trips and during the winter months. It's throwing a small evap code on my OBD2 scanner, either P042 or P046. I've replaced the purge valve and checked all the vacuum lines for leaks. I've been trying to figure this out for over a year now. The car has low mileage and had only one owner before me. I got a super good deal on it. Now I'm thinking this problem is why I got the car so cheap. I also smell gas fumes inside the car every once and awhile. I'm not a mechanic but have basic skills/knowledge and I'm not afraid to get dirty.
From my research and experience with this problem I'm guessing ECM or charcoal canister maybe. Can someone please put me in the right direction? Thank you and I appreciate your time and expertise.
Also, when filling up at the gas station the gas pump cuts off repeatedly. I have to have the nozzle barely pressed to refuel.
Collin L
Oct 17, 2022 at 3:22 PM
Advertisement
Avatar
JACOBANDNICKOLAS
  • CERTIFIED EXPERT
  • 110,175 POSTS
Hi,

I need you to confirm the codes you are getting. It should be a letter followed by four digits. For example, P0420.

Also, the idea that you smell fuel is likely related to the evap leak. However, usually when it is a small leak, you don't notice it.

Don't laugh but remove the fuel cap and inspect the filler tube. Make sure there is no rust starting where the cap seals.

Let me know the codes.

Take care,

Joe
Oct 17, 2022 at 7:16 PM
Avatar
2001 KIA SEPHIA
  • MEMBER
  • 4 POSTS
Thanks for responding so fast Joe. I just ran another diagnostic after posting my question. There are two codes showing now, P0442 and P0460. The P0460 is new, first time seeing this one. I've had a few people look at it over the past year and suggested it might be electrical.
Oct 17, 2022 at 8:02 PM
Advertisement
Avatar
2001 KIA SEPHIA
  • MEMBER
  • 4 POSTS
Oh, and the gas cap and filler tube were the first things I looked into, lol. I thoroughly cleaned the filler tube with WD40 on a shop rag and purchased a new gas cap. The engine light never went out. I even unplugged the battery for a few minutes to reset everything, but it came back on after around 30 miles or so.
Oct 17, 2022 at 8:05 PM
Avatar
JACOBANDNICKOLAS
  • CERTIFIED EXPERT
  • 110,175 POSTS
Hi,

The new code, P0460, indicates a fault with the fuel level system. I don't know if you noticed anything.

The other code, P0442, is an EVAP leak, a small leak. Here is what I recommend, you need to have the evap system smoke tested. Basically, smoke is pumped into the system at very low pressure. If there is a leak, smoke will escape from that point.

A small leak is very difficult to locate without doing this, and there are several places that it can happen. Let me know if that is something you can have done.

Joe
Oct 18, 2022 at 7:48 PM
Avatar
2001 KIA SEPHIA
  • MEMBER
  • 4 POSTS
Thanks again for your expertise. I have a mechanic buddy that said exactly what you did about getting the smoke test done. He also suggested replacing all the vacuum lines as well. Just to make sure the leak isn't coming from them. I've checked them and they look fine but they're cheap and might as well replace them. I recently ran my gas down to where the fuel light came on, which I normally don't do. I filled up the tank and unplugged my battery to reset the engine light and drove around 50 miles. The P0460 went away but the dreaded P0442 is still there lol. I really appreciate your time and help. I'll set up a smoke test this paycheck, lol.
Collin
Oct 18, 2022 at 11:49 PM
Avatar
JACOBANDNICKOLAS
  • CERTIFIED EXPERT
  • 110,175 POSTS
Hi,

Thanks for the update. I'm glad to hear you are having it smoke-tested. When it is a small leak, they are really hard to find.

If you have a chance, let me know what is found. I'm interested in knowing.

Take care,

Joe
Oct 19, 2022 at 6:34 PM