Write-up: EVAP Filter Canister Replacement for 97 Riviera (SES/DTC P0441)

Thanks for sharing, Larry. Regarding the pump seal, was the debris removed from the mounting area before Ken's replacement ring was installed? If not, maybe the height of the old material raised the locking tabs enough that the seal isn't tight enough?

No, the ring fits outside the damaged area, so it fit flat.  My SES light came on this morning, so I still have an EVAP leak somewhere.  I filled the tank and do not smell gas, so it may not be leaking anymore.  The leak may be somewhere else for all I know. I have replaced the gas cap with a new OEM cap. I may have a problem with the purge or vent valves, or a small hole in the tubing somewhere. It is a P0442 code.

I get the P0440 code once in a while, but I don't smell any fuel. Considering disabling this code in the PCM...

AA wrote:

I get the P0440 code once in a while, but I don't smell any fuel. Considering disabling this code in the PCM...

Yes, that is a different related code.  After I had driven the car yesterday, I can smell fuel in the rear wheel well on the drivers side.  I can't see any fuel leaking though.  I can see where the filler tube goes into the tank.  Looks like a section of hose with screw clamps that secure it to the tank.  I thought that might be porous, so i reached in while I was fueling the car yesterday, but I couldn't detect or smell any fuel leaking there.  I have the P0442 code, so the leak is very small.  I'll have to jack up the car, and remove the wheel to see if I can get a closer look.

My inspection is due in June, but this won't prevent me from passing.  After I reset the SES light, all the emissions readiness tests pass except the EVAP.  The PCM won't do that test until the tank gets to around 1/2.  I can prevent that by keeping the fuel level close to full.  In NY, you fail if the SES light is on, but my 98 can have up to 2 readiness tests not completed and still pass, so no big deal.  Would like to diagnose this though.

LARRY70GS wrote:

AA wrote:

I get the P0440 code once in a while, but I don't smell any fuel. Considering disabling this code in the PCM...

Yes, that is a different related code.  After I had driven the car yesterday, I can smell fuel in the rear wheel well on the drivers side.  I can't see any fuel leaking though.  I can see where the filler tube goes into the tank.  Looks like a section of hose with screw clamps that secure it to the tank.  I thought that might be porous, so i reached in while I was fueling the car yesterday, but I couldn't detect or smell any fuel leaking there.  I have the P0442 code, so the leak is very small.  I'll have to jack up the car, and remove the wheel to see if I can get a closer look.

My inspection is due in June, but this won't prevent me from passing.  After I reset the SES light, all the emissions readiness tests pass except the EVAP.  The PCM won't do that test until the tank gets to around 1/2.  I can prevent that by keeping the fuel level close to full.  In NY, you fail if the SES light is on, but my 98 can have up to 2 readiness tests not completed and still pass, so no big deal.  Would like to diagnose this though.

On mine, way back when, it was a corrosion pinhole in the filler tube, you might have to smoke it to find the leak.

Albert, I was looking at the filler tube today. It looks like it is plastic to me. How hard was it to change out? How does it connect at the quarter panel? I see the hose clamps and hose at the tank end.

I replaced my pump some time ago, it took a while to clean and point the metal to slow down the rust. It's sort of in the weather, and hidden -- just a pain IMHO.

Ken's replacement locking mounts are a lifesaver for that job.

Albert,
What is the filler tube replacement entail? Mine may be leaking somewhere, but I can't see where. I just smell the gas after I fill up. How does the pipe attach at the fender? I see the hose clamps at the tank end.

LARRY70GS wrote:

Albert,
            What is the filler tube replacement entail?  Mine may be leaking somewhere, but I can't see where.  I just smell the gas after I fill up.  How does the pipe attach at the fender?  I see the hose clamps at the tank end.

It's been a LONG time but IIRC you back out a few hard-to-reach screws on an inner fender and pipe flange and then it pulls off the tank out of the fender - you need to check.

After I replaced mine with one for a 2002 Park Ave (fits but you have to trim the plastic panel that it passes thru the inner fender) some exact replacements became available. Try this: http://www.ebay.com/itm/New-Fuel-Tank-Filler-Neck-FOR-1995-1996-1997-1998-Buick-Riviera-/122142139144

Albert, looked at the E bay filler tube. What is that second tube pictured?

LARRY70GS wrote:

Albert, looked at the E  bay filler tube.  What is that second tube pictured?

IDK. The Park Ave filler hose I actually installed looks somewhat different and it was long ago that I did the replacement. If that's the pic of the Riv filler, I assume that's an evap hose or tank vent, the air's gotta go somewhere while you are filling the tank.