Hello, I have a p0441 code on my 1996 lt4.
I have replaced the vacuum switch, solenoid canister and the charcoal canister behind the right wheel. I took it to my local Chevy dealership and they can’t find the problem. If anyone could offer advice I would sure appreciate it!

 

Can you confirm that by "vacuum switch" you're referring to the part marked 11 in this diagram?

https://i.pinimg.com/originals/68/11...6c88b28000.jpg

This is the purge valve, and is supposed to have an L-shaped rubber hose open to atmosphere on it (marked as 15 on the diagram). Many shops and owners who don't know otherwise see this hose-to-nowhere and plug it, or indeed after 25 years the purge valves do indeed go bad. If you did indeed replace it, it should have come with this L-shaped hose open to atmosphere attached. Is it still open to atmosphere, or was it connected somewhere or capped off?

If this is the part you replaced, and the L-shaped hose is present and open to atmosphere as designed, the next step is to replace the EVAP purge solenoid, marked as 7 in the diagram. And check to make sure all the vacuum hoses in the EVAP system haven't dry-rotted.

 

Thank you,
Yes I have replaced those items and the vacuum switch is open. The lines all look good I don’t see any rot at all. I brought the car to my local dealership and they couldn’t figure it out. The only other thing wrong is when I get down to below half a tank of gas the car hesitates. I was thinking about replacing my fuel pump sock. If you have other suggestions I’m sure listening. Thanks for the help and diagram!

 

No problem!

Does the car hesitate all the time, or only when you stomp on it? My car hesitates when you stomp on it with low fuel as well because, well, the fuel pickup isn't in a position in our cars to really work when you accelerate suddenly. But if it's all the time, and you're getting an EVAP purge code, I suppose it's possible that somehow you're drawing a massive vacuum in the tank that's making it difficult to pump fuel out. Easy way to find out is to pull over when this condition is happening and remove the fuel cap. Wait for the pressure to equalize, then replace the cap. If the hesitation goes away, then something is seriously wrong inside the tank. If the hesitation is exactly the same, then there's another problem with fuel delivery.

Just to check, but after replacing the parts, the codes were reset, yes? On the OBDII cars, if I'm recalling correctly, it would take 50 ignition cycles for the code to reset by itself.

In any event, if all those components have been replaced and the lines look good and the code keeps coming back, I'm afraid I'm out of my element for the 96-specific vehicles. My service manual only covers the 94-95, which doesn't use the same EVAP setup and of course doesn't include diagnostic troubleshooting for the OBDII-specific codes. Hopefully someone who does have the 96 FSM can jump in here and help out. If you'd like one of your own, they're only $20 from RockAuto. Here's a link: https://www.rockauto.com/en/moreinfo...324&cc=1041398

 

Hello,

I have a 96 and I chased some codes around with it. Being an ODBII car your good because that is the same platform going on today so many techs can look at it. But throwing parts at it is not always the answer. Verify all wiring is properly sending signals with volt meter and test light. Use an old school test light. The LED test light can sometimes show a solid circuit but its not really strong enough as it should be so its false. The old test light will be really dim on a weak signal. I have chased down two issues on my MAF and CKP sensors with the test light and volt meter. One was a weak signal and one was no signal.

I am not sure what state you are in but in TX at 25 years this car can be registered as an Antique and these items in the PCM can be turned off and no longer needed for that type of registration.

 

I cannot for the life of me find the evap switch for sale or even listed as a part that fits my 96. Can you/someone please point me to where to find one? The only ones I can find only show fitment for GM trucks. I too am having this issue with the code and have so far replaced the canister and the solenoid. I’m thinking of replacing the valve now and this evap switch. The solenoids and valves are sold by every corvette retailer but not the switch?

 

I bought one from RockAuto by searching the part number. It was not shown by the seller as correct for my car, but I bought it anyway. It was, in fact, the correct part.
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Prior to my purchase (above) my local dealer ordered one for me - and it was the wrong part. They did not order by part number but rather by vehicle.

 

thanks. I did find one on auto zone that seems correct Duralast SW9519 so hopefully it works. Also ordered the valve which I did not replace when I did the canister. Hopefully these two things fix the issue because I’ve replaced everything else but the line and I can’t imagine that would be easy!

 

The long line between the charcoal canister and the switch can accumulate charcoal bits, which, if ignored, can cause a new switch to fail quickly. I suggest disconnecting that bit of tubing at each end and using compressed air to blow it out.

 

Yeah, so when I originally got the code I only did the solenoid. CEL ended up coming back so I replaced the canister, and solenoid again and made sure to blow out the line. CEL is ended up coming back second time driving it so I’m going to replace the valve, switch and the short vacuum line between solenoid and switch. That’s pretty much every part in the system except the line between canister and switch so if this doesn’t work I guess that’s it? Idk what else to do if this doesn’t fix it. Frustrating