po441 no purge flow detected.
4.3l vortec. vin w. cpi motor.
ive replaced the purge solenoid. cause when supplied 12v it did not click and you couldn't blow through it. the new solenoid tests good. new gas tank vent valve, since it was busted off.


I blew through the line at the evap solenoid and had somebody listen at the gas tank while cap was open and you can hear hissing. so the lines aren't clogged. there was some resistance when I blew through it though. that was before I replaced the one of the gas tank vent valves that was busted and capped off. so now I might have better flow. haven't tried it again.


the solenoid gets 12v when key on.


my question is what does the one sensor behind the evap solenoid do? ive looked it up and its called the evap vacuum switch or something like that. im wondering if that's what actually detecting the flow and that it failed and cant detect any flow. thus spitting out this code. how do I test this sensor before I buy a new one?


thanks

 

so anybody have an idea what that sensor actually does. ive looked through it and you can see through it, it has little lines or bars going side to side in different directions.


does this thing act as a mass airflow sensor or is it like a pressure switch.

 

Post an image of it, that might help.

 

 

its the one to the right of the oil fill tube

 

so can anybody tell me what that sensor does, and how to test it.
im going to blow out the lines with compressed air to see if that helps. and if the evap box can be taken apart without being destroyed then I might clean that out too.

 

any ideas?

 

Probably long answered but The sensor tells the computer that you have flow/vac for the vent system. If it sees nothing, you get that infamous code 441.

 

I have actually fixed this problem. I rebuilt the evap canister. and the code never came back. I cut it open replaced the filters and the activated carbon and then sealed it back up. heres a video I made.

 

I changed my idle control valve on my ,98 and when done started truck and it revved so high thought it would blow up. Shut it down and manually adjusted throttle. BAD mistake cuz they adjust themselves and mine hasn't been the same since. I trying taking off the throttle body and cleaning it up first to no avail. Just change tcs valve and hope it works. Bank 1 is driver side. Sensor 1 is on manifold and 3 is past cat. Bank 2 and 4 is the opposite