Charcoal canister box.

After changing the purge valve and the vent valve, a smoke machine revealed I need a charcoal canister box to remove a code and pass inspection ( I forgot but think it was p0440). I am sending my PCM out next week for a tune and I can get the EVAP sensors removed at the same time.
Do I still need to change this box, my car runs fine? Will it greatly affect gas mileage or eventually get stuffed up like a catalytic converter? by the time I'm done with a par and installation it's going to be around $200, do I need to put this part in or just have the sensors tuned out? I may replace the gas cap with a stant after searching on this site just a rule that out as well.

It's EASY to get around the inspection without doing anything. I have had a P0442 code for the last 5 years and passed inspection every year. If you have a CEL, reset it first. Then keep the tank full. Keep topping it off every 100 miles or so. The PCM will do all the readiness tests one at a time. It will not do the EVAP readiness test until the fuel level is between approximately 1/4 and 3/4. 1998 cars are allowed up to 2 readiness tests not complete and it will pass in NYS. 2001 and later, one test not complete allowed. I have a small leak somewhere. I have never had the car smoked. It doesn't affect engine operation or efficiency at all. It's just a small EVAP leak somewhere. I'll get to it one day, maybe.

It's EASY to get around the inspection without doing anything.  I have had a P0442 code for the last 5 years and passed inspection every year.  If you have a CEL, reset it first.  Then keep the tank full.  Keep topping it off every 100 miles or so.  The PCM will do all the readiness tests one at a time.  It will not do the EVAP readiness test until the fuel level is between approximately 1/4 and 3/4.  1998 cars are allowed up to 2 readiness tests not complete and it will pass in NYS.  2001 and later, one test not complete allowed. I have a small leak somewhere.  I have never had the car smoked.  It doesn't affect engine operation or efficiency at all.  It's just a small EVAP leak somewhere.  I'll get to it one day, maybe.

It's EASY to get around the inspection without doing anything.  I have had a P0442 code for the last 5 years and passed inspection every year.  If you have a CEL, reset it first.  Then keep the tank full.  Keep topping it off every 100 miles or so.  The PCM will do all the readiness tests one at a time.  It will not do the EVAP readiness test until the fuel level is between approximately 1/4 and 3/4.  1998 cars are allowed up to 2 readiness tests not complete and it will pass in NYS.  2001 and later, one test not complete allowed. I have a small leak somewhere.  I have never had the car smoked.  It doesn't affect engine operation or efficiency at all.  It's just a small EVAP leak somewhere.  I'll get to it one day, maybe.

carguy8888 wrote:

After changing the purge valve and the vent valve, a smoke machine revealed I need a charcoal canister box to remove a code and pass inspection ( I forgot but think it was p0440). I am sending my PCM out next week for a tune and I can get the EVAP sensors removed at the same time.
Do I still need to change this box, my car runs fine? Will it greatly affect gas mileage or eventually get stuffed up like a catalytic converter? by the time I'm done with a par and installation it's going to be around $200,  do I need to put this part in or just have the sensors tuned out? I may replace the gas cap with a stant after searching on this site just a rule that out as well.

One way to look at this -- are you taking a hit on gas mileage. An EVAP leak *can* hurt gas mileage but whether it actually does depends on weather and stuff.

What I'd consider doing -- get a junkyard canister from a pick-n-pull for short money. Lots of GM cars used the exact same canister, for instance the 2005 LeSabre, Park Ave, Deville, Bonneville... and many more - look at the part on RockAuto.com, click on the part number to get the interchange list... Just in Buicks the PNP near me has more than 10 such cars. They charge $9.09 per canister, you pull. New they are $75 - $100.

Just saying. IF your gas mileage is off, for $10 and some time you can fix it.

I have a code scanner w/ the readiness monitor which I used. It went straight from three open monitors to the ses light illuminating. I do know about the the two readiness monitors rule but not keeping the tank full. Now that I know it does not affect gas mileage or operation & I have no fuel smell I will not buy the box, omit the sensors b/c the pcm is going out anyway & follow your instructions with the code scanner. I will by a new AC Delco gas cap b/c it is less than $20 & save the $200 ish from the canister. Thanks again Larry.

Albert,
Between the $100 on Rock auto and or Amazon for the part and the install I'm thinking it won't pay for the difference in mileage & I am not pulling or installing it.

carguy8888 wrote:

Albert,
Between the $100 on Rock auto and or Amazon for the part and the install I'm thinking it won't pay for the difference in mileage & I am not pulling or installing it.

l understand. Difference might be that I drive a *lot* of highway mileage, and can see the difference using my scanner's calculation of MPG when there is an evap leak. I'm not sure I'd spend the $100 but the $10 and a few minutes for the pull, yeah, just to not have to mind the light if only because if the light were to trip for something that was somewhat more serious I would not know until it was probably too late, if it was on all the time.

I know you drive a lot, are you close to 400k yet?No lift or mechanical hands here so I am going to throw on a gas cap, delete the evap sensors only and call it a day lol.

carguy8888 wrote:

I know you drive a lot, are you close to 400k yet?No lift or mechanical hands here so I am going to throw on a gas cap, delete the evap sensors only and call it a day lol.

 less than 20K to go, to hit 400K... I have missed 2000+ miles of driving due to the pandemic, since I can't visit my dad (no visitors at his facility) there's no sense in the drive. My guess is the earliest I'll be allowed to visit is Memorial Day, and that's just a SWAG.

Wear Your Mask and carry on.

Albertj

Ditto lol.

With the tune the light is gone and the car is inspected. Should I bother changing the gas cap since it's only 20 bucks for a good one? How can you tell if the gas cap is bad?

You can't unless there is very obvious damage to it. Unless you want to have a service facility test your cap.

https://www.pepboys.com/stant-mechanical-fuel-cap-tester/product/8994402

carguy8888 wrote:

With the tune the light is gone and the car is inspected. Should I bother changing the gas cap since it's only 20 bucks for a good one? How can you tell if the gas cap is bad?

You can't unless there is very obvious damage to it.  Unless you want to have a service facility test your cap.

https://www.pepboys.com/stant-mechanical-fuel-cap-tester/product/8994402

Caps are easy to get at GM dealers, junkyards, etc. I would not bother, I would rather have replaced the evap canister.

I have replaced several gas caps on my Riv. If you're gonna buy one, get a GM one. The Stant caps are OK new but in my experience only last a couple three years, I think it's the gaskets not the mechanical vent that is the problem.

Should I bother to replace the cap because I don't know if the problem is the cap or the actual canister under the car which I'm not going to replace?

Why is the SES light gone with the tune?

I removed the EVAP sensor light

carguy8888 wrote:

I removed the EVAP sensor light

I have no idea what that is.

Sorry LOL, I had to tuner tune out the EVAP sensor so it will not throw any codes. It's a feature they have. Now I have no codes and my SES light is out.

carguy8888 wrote:

Sorry LOL, I had to tuner tune out the EVAP sensor so it will not throw any codes. It's a feature they have. Now I have no codes and my SES light is out.

OK, that will work, so the PCM will never do the EVAP test regardless of fuel tank level.

Exactly, I did not convey it correctly. So should I bother getting a gas cap for twenty bucks, I'm thinking there's a 50-50 shot it will help the leak?

What leak?  You wouldn't know you had one if not for the SES light, LOL.  Do you smell gas?  Have you ever looked at the top of the tank under the access cover?

I don't smell gas and I never met the inside of the access cover lol. Is there any advantage to fixing the leak?

How do you plan on doing that? How would you know you fixed it? Unless you get the car smoked, you won't know where the leak is. Take the access cover off and have a look. It is not uncommon for the tabs that hold the fuel pump to the tank, to rot. That can create the leak all on it's own.

I would not know if I fixed it. just willing to throw away the twenty on the cap. Not too sound stupid, I did not know this panel existed. I guess I need to look on one of the sides of the trunk?

carguy8888 wrote:

I don't smell gas and I never met the inside of the access cover lol. Is there any advantage to fixing the leak?

Yes.

You can't make the pump lock ring fail when it is convenient for you. So the advantage of finding and fixing the leak(s) is you maintain control and driveability - after all, when (not if) that ring pops you won't likely be driving at all, all of a sudden, even if you're say on an interstate.

I don't think I have any more to add.

Albertj