Hi,


I replaced my evap solenoid at the intake manifold and for 4 weeks there was no code. All was well.


Then I got the dreaded p442. I know that using a smoking system is probably the easiest way to find it.


My question is, perhaps I made a mistake putting the solenoid on.


The screws holding it down are tight.


I lifted the old one off and put the new one straight down into the spot.


there was nothing else in the evap solenoid "box" from the store. And there was no gasket when I took off the old one.


I pushed the white clip so it went down ( it didn't come off ) then I just attached back onto solenoid.


Pressed white clip and calling it day, worked for 4 weeks.


Did I miss anything?


any advise?


http://www.justanswer.com/chevy/4tqz...ions-leak.html


Also I tightened gas cap click click click too.


I have a mighty vac I could use to test lines if need be.

 

I found a good link : https://blazerforum.com/forum/diagno...plained-35144/


Just let me know if you can think of anything right off the bat based on what I've said.


Oh an fyi the canister back at tank it brand new too.

 

The traditional glib answer for a P0442 EVAP system small leak is to 'tighten the gas cap.' That's good advice ONLY if you fail to completely tighten the cap after filling the tank. Most people don't do this , esp. those on this forum. I have a better answer. Replace the big 'O' ring on the gas cap. My 2003 gas cap had a cracked O ring. I went to the NAPA parts and got them to look in the O ring drawer for the largest one they had and it fit perfectly. Carefully remove the old O ring with a pick. Then install the new O ring. Then erase the DTC code and drive it. NAPA charged me 0.74 cents for this. Lot's cheaper than buying a new gas cap. My DTC hasn't come back on.

 

"Small leak" is defined as a leak approximately .030" or smaller, (a little bigger than a pin). Instead of looking for a needle in a haystack, you're looking for the hole it created Follow the flow chart in post #2, it will pinpoint the leak, (no pun intended). The fuel cap O ring is a good idea, and also check the steel fuel filler neck, they like to rust out.

 

When I started having the DTC P0442, I researched it on this forum and also called 'Sam's (Memmolo) Garage radio show. In summary, they were saying it is probably a bad gas cap---17.00 to 20.00--- or a bad EVAP canister at 132.00. The proper procedure was to get a 'smoke test' done at a competent $hop. That is a 45.00 or so trip. They run smoke throughout the system and you can see the smoke coming out of the leaks. This would be great if the 'small leak' is a cracked hose.
I like to do the cheap and easy repairs first myself before I take it in to a shop. So I removed the gas cap and looked inside and sure enough the gasket was flattened and had cracks about every one inch all the way round the ring. I tried to get just a gasket or O ring, but of course, you have to buy the entire gas cap. I then went to my friendly NAPA parts guy and asked them to look in the tray and get me a large O ring to fit this cap. I had the cap in hand. That was the 0.74 cents deal. Then I removed the old ring and it was a special design. It was a basic O ring but had a groove formed in the outer edge so it would compress better. If you had cut it, the cross section would look like a 'Cee' Only the top part that touched the gas filler pipe was cracked. The bottom of the Cee which rested on the cap was not cracked. I thought that these cracks probably weren't causing the DTC. I went ahead, installed the new O ring, cleaned up the gas filler flange with Scotch Brite, and reinstalled the cap. Then using my scanner, I 'erased' the DTC P0442 and put old '03 SUV back on the road. I have driven it over 100 miles since then, various short trips to town and back, and the dash has not displayed any DTC. Very happy. One other comment is the location of the EVAP canister. It is inside the rear fender panel behind the gas filler cap. It is low and open to any road debris the driver's rear tire might kick up such as rocks, sticks, gravel and so on. I would think the GM engineer's would have some sort of protective cover over this fragile black box. Is there an aftermarket cover you can buy?