: EVAP switch, purge solenoid, i butchered it

12-14-09, 10:29 AM
This pic is from a 97 seville. My 97 STS is not the same. I either have te wron switch, or i am missing a peice. The peice i have that the 2 vacuum lines go into is a black rectangular box with an electical plug. The plug from my wiring harness is plugged into it. The switch in the picture is NOT what i have (#2), and i do not see the square box in that picture.

Am i missing a part or do i have the wrong part?

I believe this is the cause to my 02 sensor codes and the 1441 EVAP System flow during non-purge code. I am returning a dead alternator to the scrap yard today and if i do indeed have the wrong switch i am going to look for the right one.

12-14-09, 10:57 AM
this is what is on my car now:

12-14-09, 10:21 PM
anyone got a picture of a 97? Top of the engine rear valve cover? I think i know where i went wrong... I looked at some cars at the scrap yard today and none of them have the square piece, they all have the round one. I may have left the square one bolted to that 95 engine when i put it in and didnt put the one on for my 97.

12-15-09, 08:34 AM
The top picture shows what I think is a flow sensor while the lower one shows a purge solenoid.
These won't affect an O2 sensor code but if the solenoid you do have is connected backwards (vacuum hoses) it can cause flow during non-purge.
I don't usually see that on Cadillac but I have seen it on Chevy's that use that same setup. Guys swap the hoses when they do an intake and boom.

If the sensor is bad (#2) it will set a flow during non-purge code. If you follow the vacuum line back from the solenoid (post 2) you don't see the sensor (#2 post 1)?

12-15-09, 11:38 AM
my vacuum line goes from intake to the pic in post #2, and from the pic in post #2 down into the car somewhere. I have tried reversing the lines and still get flow during non-purge. I do have a loose plug hanging there but i thought it was for the A/C (the A/C lines are removed, compressor shot, replacing in the spring). Could be that that plug is for a part im missing, but it looks identical to the plug that plugs into the A/C line at the passenger side firewall.

12-16-09, 08:27 AM
This diagnostic test is used to determine if the Evaporative Emission (EVAP) control solenoid is open (passing vacuum) when the PCM is commanding it closed or if the EVAP vacuum switch or circuit is open. The Evaporative Emission (EVAP) vacuum switch is a normally closed switch mounted in the vacuum line between the EVAP canister and the EVAP solenoid. The switch opens when vacuum from the engine draws the evaporative emissions from the EVAP canister through the EVAP solenoid and into the throttle body. The PCM monitors the state of the EVAP vacuum switch to determine if the EVAP solenoid is open and passing vacuum. The PCM accomplishes this by monitoring the amount of time the EVAP vacuum switch is continuously open or closed with purge off. If the switch is open during the test conditions for 9 consecutive seconds, DTC P1441 is set.