Need4Camaro

iTrader: (1)

99 Z28 with all the problems in the world.

Its got a SES for a P0440 and I already replaced the Gas Cap with a AC Delco unit and the problem is still recurring. This problem is also strange, I only get this code when I'm down to about 1/4th tank of fuel, but I have to pass emissions so I need to fix it.

What is the common cause for this issue and the fix for it? Can someone point me to the exact name of the evap canister on the fuel tank?

dp121

If you are in a big hurry to pass emissions just clear the code and make sure your tank is full when you get inspections done.

Not sure on the fix though. I had that code last summer and a new generic gas cap fixed it.

dp121

I did a quick search for P0440 and found this. It is very informative and should help you.

https://ls1tech.com/forums/general-m...ap-system.html

Need4Camaro

iTrader: (1)

I got alittle bit lost in that thread, is that thread speaking of 3 different parts of which seemingly serve the same purpose?

A fuel tank vent?
A EVAP cannister purge valve which is located under the Fuel Tank?
and another EVAP cannister purge valve on the Intake? meaning we have two of them? or am I missing something?

dp121

No there's only one EVAP canister located in front of the left rear wheel. There are pics of it in that thread. They also talk about the rest of the EVAP system and show pics of parts that can go bad and cause a P0440 code.

Need4Camaro

iTrader: (1)

What is that part near the intake / throttle body that they're speaking of?

And can I get part numbers for the EVAP Canister infront of the left rear wheel? I'm assuming this is probably the part thats bad as it appears only the 98's had the Fuel Vent in the vulnerable area, if not though does the fuel tank have to be dropped to access the Fuel Vent? (I'm very hesitant about drilling the trap door above my fuel lines)

dp121

I was thinking it may be a good idea for you to go to the library and get a repair manual for your car. It may help quite a bit.

There is a ton of info here at LS1Tech about the EVAP system and code P0440. Maybe a search and the repair manual together will help.

Need4Camaro

iTrader: (1)

Thanks for the suggestion and it would help to know a bit more inside and out but time for me is extremely constrictive, I am typically working between 1 PM and 2 AM Monday thru Friday and on the weekdays the remaining of my off work time is spent either taking care of other issues or sleep. Weekend is about all I get to fix on my car and I have to do it in a hurry so I can get it running again by Monday.

I actually did search for the evap cannister on LS1 tech but I am still a little confused on the subject because there are several parts involved and I can't find which part number refers to the device near the axle (or if

I saw this part on Rock Auto:

It costs $14.04 - but it also states an additional wiring harness adapter is needed because GM changed the part. It appears to cover the following PN's (10293954, 13575703, 2141690) I am THINKING this is the part you were talking about but I'm not 100% sure.

I also saw this:

This is much pricier but is listed as the Evap Cannister (I'm thinking it really meant Evap Charcoal Cannister) and I BELIEVE its located ontop of the fuel tank. per this thread: https://ls1tech.com/forums/general-m...ment-help.html
Once again Im not 100% sure but any confirmation would be greatly appreciated.

dp121

Well one thing I would do is check and make sure that the canister is indeed the problem. I know that a vacuum leak can cause that code. Maybe just take a quick look around your canister and see if anything looks suspect.

Need4Camaro

iTrader: (1)

Ok so I finally got a chance to get under the car and have a look... I didnt really see the fuel vent or evap cannister...



This photo of the body harness connectors and the fuel vent hose is npt extended to this bracket...



whats that hose at the top that has nothing connected to i indicated bybthe red circle? That photo was taken looking directly up at the fuel tank.

im-not-guilty

iTrader: (4)

At minimum You need a scan tool to with output controls to diagnose this ..

You may need a smoke machine ....

440 is a evap leak

Vent valve that is suck open or won't shut all the way ...
Purge valve that is working incorrectly ..
Fuel tank psi sensor reading incorrectly ...

As a rule it's not the canister or fuel cap ??
It can be but unlikely

Not sure if your in the rust belt but that could open a whole other can o worms
Rusty fuel,filer rusty fuel tank or sender

Need4Camaro

iTrader: (1)

Meh, Im a decent mechanic but in this case Im going to have to take it to a shop as I have neither one of those and I dont have time to throw money away at it and fail emissions.