Ok, not quite a blood hound but it has a nose like one. Almost every time I pull into a gas station my car starts sniffing around and the check engine light comes one. I finally got a OBD2 scanner and it gave me a code and said small leak. I forgot the numbers, any ways this is my answer in removing the engine light from the panel. (By the way I always shut the engine off as soon as I pull into the pump area.)

I was told by a mechanic that it could be anyone of 10 sensors and that could cost a lot of money.

Sooooooooooo I was wondering if anyone has this problem or does anyone know what sensor might be going bad so I can replace it with out a mechanic spending all day on trying to find it.

Last fall I was mowing the yard and had to fill the lawn mower and I was about 10ft from the H3 and the next morning the check engine light comes on.

Just looked up the code and it is a: 0442 EVAP emissions control system leak (SMALL)

Any help would be appreciated!

 

I've had it twice on 2 different H3s. Both times it was the gas cap seal.

 

Thanks: Did you replace the seal to correct the problem?

 

I had to replace the gas cap/seal. One unit. I had a locking cap for a long time then the lock cylinder got buggered up and I put on an OEM one.

 

Usually, not always, (80% of the time or so) when you have a fuel cap leak the DIC will display "Fuel Cap" and the CEL will trigger. Even a small nick in the cap seal can cause it, as well as just a dirty seal.

An EVAP leak usually mean just that. Check the EVAP hoses/connections, start at the TB and follow through the purge valve solenoid.

 

On overnights and my brain is foggy so thanks for the info and TB means?
Where might one like me find the purge valve solenoid?
Thanks Doc

 

"Throttle Body". That is a vacuum source for the EVAP, just follow the black hose connected to the front top to where it goes around and under the intake manifold to the control valve, from there down under the truck to the fuel tank. If it come loose, gets cracked, or chafes a pin hole, that is your problem.

They have been known to get dry and crack, possibly just be a tad loose where connected to the TB & or control valve.

#1,12, 5 & 14

 

Those are good suggestions and probably more comon than mine. Mine had a code when i bought it. The reader said the evap vent selinoid. So it was the first of only 2 trips to the dealer( i fix myself now) and they replaced the little can in under there and the mounting gear. They told me it was either from having a leak in the hoses and it sucking in exhaust fumes to the selinoid or from leaving it running while pumping gas in. The code went away after that. Was like $150 or something. Can't remember cuz i got more stuff done The same time...and is why i fix myself...1700 bucks....rip... Anyway i don't know how c'mon it is but someone told me i could have possibly unhooked the tubes which i assume is Tue same one doc is referring to from The can and tried to let the fumes out while battery is unhooked. Then reconnect them. Sounds like a maybe it will maybe it won't deal to me.

 

Excellent schematic Doc!

Couple weeks ago, I was pumpin' fuel in the tank, fuel nozzle kept shutting off? I had to pull the nozzle out and put it back in, after a couple seconds, shut off again, kept doing that for 10 or so minutes, only got 10gallons of fuel. I drove home and put the scanner in and found a code P0446, traced it to the vent solenoid, and started searching online for the part. ACDelco shows the part #214-2241 for the H3 with the tube as a direct fit,(List $345.00) however I found the solenoid without the tube on amazon ACDelco 214-2147 (gm#25932569) for $15.36, added another item that I needed, to get to $25.00 for FREE shipping. Pulled the canister(2 line connectors, 1 electrical connector, & 1 bolt. Took it to my kitchen sink, ran hot water over the line, and pulled it apart, installed the line on the new solenoid, (still using the hot water). Installed the assembly back into the truck, and all working with no problem.

BTW, ultraclassic01, replace the fuel cap, cheap fix, if that corrects your problem, if not, you will eventually need a NEW fuel cap. Common problem on GM, even a TSB on the H3..

 

DOC, BOTH times it was just a check engine light and NOTHING on the DIC. After checking the code at the local Murray's (now O'rileys) I got the 0442 small evap code. Went to the dealer (under warranty) and they replaced the cap in the service lane while I waited. Cleared the code with their OBDII and no more check engine light.

I have also had the Large Evap code and the Canister replaced on another due to too much mud and filth-flarn in it.