I was wondering what that was too after I took it off my intake today lol

 

I've never seen that before. Looks like it is in the Evap vacuum lines?

 

Hey shakenfake, can you look and see if there is a part # on that, since you have it off?

 

the canister vapor gas ... PCM turns on the electrical vac valve the engine starts valve runs a few minutes ...charcoal sucks out the gasoline fumes ...
also fix the canister hoses inspect it ...in the right front tire fwd behind the bumper...

 

I will try and remember when I get home. I believe it is related to EVAP is what I came up with.

 

Charcoal Canister Purge Valve?

 

It’s the Evap Vacuum Switch, can anyone with a FSM manual get a part # for me, I Googled it but they look different than the original one.

 

Correct. GM added this for the 96 model year for OBD2 compliance. The '94s and '95s don't have it. I really like @1slow96 's idea of relocating both this and the purge solenoid itself down to the evap canister to get it out of the way and away from engine heat.

 

Yep EVAP valve. On the nipple that faces towards firewall, is just a 90 degree elbow vac hose that goes nowhere (read you don't need it). The front nipple vac hose goes to EVAP canister under PS fender. For us that have the "vette" engine covers you need to remove the mounting bracket and just lay it under those covers

 

EVAP vacuum switch -- like a vacuum switch. 17089068 12555984
Calling it an inline "sensor" might have avoided some of the confusion. It is a separate component from the purge solenoid valve.

(sherlock9c1 just beat me to it, was going to say I'm pretty sure this was added for OBDII)

 

I have not found a part number for the diagnostic switch yet. I also do not see it offered on RockAuto. This is 1996 model year.

 

This is the1996 core support label

 

AP9 where did you find the part number? I searched the parts catalog I have and didn't find it.

 

Thanks AP9, I searched that # nothing came up discontinued.

 

used a vacuum gauge engine starts then did the PCM vac switch turns on and open the valve ............
did you post your codes ??????????
if you inspected the canister/hoses/electrical components then failed the part ...
now it todays ,,,, many parts are not manufactured ...
a person on the forum he changed the canister charcoal .. changed the charcoal in the canister ...

 

So are you saying we don't need this?

 

IIRC if that valve is disconnected or clogs it throws a CEL

 

Interestingly, this EVAP - CANISTER PURGE SWITCH / purge vacuum diagnostic switch / purge sensor 12555984 shows up in the internet-based GM parts usage catalogs as being used with LT1s in F and Y cars, but not B and D. Unintentional omission perhaps? It is listed in the General Information: Part Numbers section of the SS Handbook PDF.

Relevant DTCs if it's malfunctioning, missing, or detecting a problem:
P0441 - EVAP System No Flow During Purge
P0443 - EVAP Purge Solenoid Control Circuit
P1441 - EVAP System Flow During Non-Purge


Although the FSM doesn't explicitly state so, I wouldn't be surprised if those faults also limited or restricted the solenoid purge valve (which is controlled by the PCM) from opening, or from attempting to operate "normally" while driving. This is pure conjecture, based on how I have seen more modern EVAP systems function. Not enough purge = oversaturated canister, leading to breakthrough (vapors can then escape out the fresh air inlet) but in practice there's always going to be some "breakthrough" on any vehicle with cracks or leaks in the vapor hose leading back to the fuel tank.

 

Change the charcoal in the canister? How do you do that?

 

Dorman Products - 911-072

post your codes .. I have MY 1996 OEM chevrolet impala manual ....

 

P0441
P0443

 

The p0443 evap purge solenoid is the control circuit ...look up the .75 DC amp the pink wire A TO solenoid ...the series to the pink wire to the solenoid ,,, also use the OHM meter around 15-18 ohms pull the connector OFF , solenoid then ohm it ...engine starts up and it is around 25 sec then the solenoid shuts down the PCM ..
use the voltmeter engine turns on 0-25 sec the solenoid the connector on the solenoid pink and DK GRN/WHT ..
PINK WIRE IS TO THE FUSE 20A EMI FUSE 4 under hood , AND THE DK GRN /WHT TO THE PCM ..

THE P0441 code is not working the evap system no flow purge now so the p0443 is a failure ,, solenoid coil open /pcm is the connector corrosion pins / the fuse 20 amp open under hood ...
the O2 sensors are the same 20amp fuse .................

 

Appreciate it, Thanks Roy.

 

Mine would always clog up with little balls of carbon,being that I'm so frugal,uh cheap ass,I would remove , knock the carbon out of the switch and sensor and reinstall,finally got tired of it and fixed it right,put a inline gas filter in the hose to keep the little balls of carbon out

 

Nice, post a pic.

 

For the switch in question, this weekend I used this Fasco 12556356 and while there I swapped out the solenoid Dorman 911-072 as well, can't make a career of troubleshooting that P1441. I while ago I also replaced their connecting hoses and added clamps to keep them tight. Warning: if a garage touches your engine in this area they will screw it up.

 

Yes, it is the evap purge valve but my question is does it have a third piece on the back that is not being used at all. because I have one that doesn't have that third back piece next to the connector port.

 

I have a question for you how can I find this one in the picture that you have up here cuz I'm looking for one as we speak????

 

Evap Vacuum Switch.
GM part# 12555984