Evap code

Hey so the riv is having problems again. This time it’s throwing a serious evap code. I’m hoping it’s something along the lines of a hose or a fuel filter. The code is for air flow during non purge. I’ve already replaced both purge valves. Not sure what to do but she’s not been running 100%. Any suggestions would be nice.

...specifically which code is it? P0440? A bad gas cap can cause that code.

"Omygoodnessiamthrowinganevapcode" - can't help you with that. But, kindly post the actual code and list what you've done about it, also mention whether you have a copy of the factory manual, then I (we) have some place to start.

Also, What year is the car, how many miles and do you live in an area where they apply salt to the roads in the winter i.e. Rust Belt.
Would be helpful knowing that info for possible problems in addition to what Albert asked.
I had evap issues that ended up being the gas tank, fuel pump mating surface rotted.
The tank is plastic yet the part on top of the tank where the fuel pump is installed has a steel ring molded into the tank to allow the fuel pump to be secured with a lock ring. Worked real well for me until it didn't. I ended purchasing a NEW OEM tank from an on-line GM seller of parts who had a tank for my 98.
Also found an new OEM fuel pump on a Ebay auction and got the pump for 1/4 of what they wanted on-line. got lucky with the pump but the tank was a lot and the labor to install was no walk in the park.
I sincerely hope this is not where your possible EVAP leak is coming from.
So, once again, more info is needed.
Rick

The code is p1441 flow during non purge. It’s a 97, yes roads are salted during winter. It has about 142k on it, as for everything I’ve done to try to fix this. I’ve done the gas cap, both purge solenoids replaced, basic tune up (plugs, oil change, air filter, harness) and I’ve hoped and prayed but absolutely nothing. Mechanic said he smoked it but it’s a possibility he didn’t see something I assume, or if he even actually did it, idk.

Ian,
Under the carpet in the forward part of the trunk is a bolted/screwed in panel that will give you access to the fuel pump for inspection, removal and replacement.

You might want to see if you can get a good look at the pump mounting flange. If you can't determine that anything is leaking by visually looking at it then you can leave that inspection cover off and have your guy run a proper smoke test to see if the EVAP leak is coming from the fuel tank to Pump mounting surface.

Heck, you may get lucky and see a split plastic or rubber hose for the EVAP system and be able to fix it from the trunk.

Otherwise the removal of the tank is quite a few hours. Hope you have a heated garage to work on it this time of year.
I was lucky, sort of speak, that mine failed in the summer time. Because I couldn't work on my car at the time due to serious back pain, I think the total cost with me buying the tank and pump, then the labor to have my shop do the replacement of all parts and clear all codes for my State inspection was a bit over $1,000.00.
Don't mean to shock you. There may be other sources for the parts NOW that are cheaper than what I had to pay (8 yrs ago) and hopefully you can repair your issue with some hose replacements and maybe a fuel pump to tank gasket. Just be sure you spray the heck out of the fuel pump mounting flange with some quality penetrating spray repeatedly before you try to remove the steel ring holding everything together. And there is a special tool, most good mechanics will have it. But if you have to buy one yourself they are not too expensive at all. Available on Ebay and Amazon from what I remember.
If you have any more questions don't hesitate to ask. I can pull the folder I have for that whole job if you need more specific info.
Always willing to help with the data I have. I'm just not near the filing cabinet for my Riv stuff at the moment.
Rick

Koswiththeriv wrote:

The code is p1441 flow during non purge. It’s a 97, yes roads are salted during winter. It has about 142k on it, as for everything I’ve done to try to fix this. I’ve done the gas cap, both purge solenoids replaced, basic tune up (plugs, oil change, air filter, harness) and I’ve hoped and prayed but absolutely nothing. Mechanic said he smoked it but it’s a possibility he didn’t see something I assume, or if he even actually did it, idk.

The mechanic may or may not have been looking at the tank top when smoking.  Time for you to remove the access panel in the trunk and look at the place the pump mounts in the tank.  It would be good to have a wet dry vac to get debris off the thing.  To get to it you need to remove the trunk carpet, then the access panel will be obvious.  Remove the screws and then in the opening you will see the tank top at the point where the fuel pump installs.  Visually inspect and smell for fumes. Supposedly it is a sealed system and you should not smell any fuel fumes, use your judgement... If you do smell fumes, probably time to disassemble/clean/seal/reassemble. As Rick W pointed out, a kind of thankless job.

Also carefully inspect (sight and smell) the area around the charcoal canister (looks like an oversized Spam can near the fuel tank and trunk.  You are looking for rust on the tank and lines.  Check the rust for potential perforation.

Here is a thread you can read through for fun -- also gives you hints if perhaps someone worked on your evap system before and got it wrong.
https://www.3800pro.com/forum/dtcs-problems-troubleshooting/39569-p0441-code.html

Also, as you know one of the things that will set off a P0441 is a wack gas cap or gas cap gasket. The GM caps have better gaskets and guts than the aftermarket ones, but in my experience the aftermarket ones are OK new -- they just don't last more than a couple years. A GM cap will work a very long time. You'd think Stant/Gates would do better. I don't know who made the OE GM caps. *point is* it's unlikely but maybe your replacement cap was bad new.

Oh and another thing. One problem I've had in the past is crud on the filler opening causing a leak. Consider using some sandpaper or a stainless steel pot scouring pad to clean the fuel filler opening to smooth. Try not to remove the plating. Then the gasket will seal the tank opening properly instead of leaking unmetered air into and fumes out of the system.

Also a possible faulty fuel tank pressure sensor ....

The general problem with the GM manual is that it does not cover what was un-knowable at the time it was written, in this case the effects of age and chemical deterioration on the components of any of the car's systems.

One effect of age is an accumulation of water vapor in the fuel tank. Over time, atmospheric air in the tank leaves behind water vapor, which condenses and accumulates. This does not happen so much any more with the alcohol-mix fuel used in the USA but it can happen depending on driving conditions.

Another effect of age is corrosion that affects how the system is sealed. So you need to check, for instance, the fuel filler pipe and associated vent, as well as the tank top where the pump assembly is mounted.

In general this sort of problem is a pain to diagnose and fix -- but once fixed properly you probably won't have to do anything about it again for as long if not longer. Meaning that if you have 135K miles on your Riv now, fix this issue correctly and you won't see it again for at least another 100K or more.