what sensor is this above the map sensor? on the gsr mani? my minifold is missing this... do i need it?

 

looks like an evap sensor/system possibly, hard to tell completely from the pic included. does small rubber hose attach to the nipple on it?

 

probably lol i dunno. its not my pic lol. im just seeing if i need it cuz my mani is missing that

 

evap purge solenoid I believe.. for usdm ecu's and emission purposes.

 

if using an obd1 ecu, you don't need it. if obd2, then you do.

 

Only if its a USDM obd2 ecu.. JDM units dont look for these sensors..

 

that is defiantly the evap purge solenoid. I used a junkyard SOHC to put on my b16 cause mine was broke. Didn't notice a difference with or without lol

 

true. seems like the majority of people use usdm ecu's though

 

oh i see, ima probably be using obd1 gsr ecu, so i should be fine without it correct?

 

yes

 

correct.

also correct.

Basically, there's a valve in the fuel tank that releases fuel vapors into the charcoal canister. When the pressure gets high enough, it opens the evap purge valve and allows the fuel vapor to flow from the charcoal canister into the intake manifold to burn. The catalytic converter then cleans the exhaust, thus reducing emissions.

It's for emissions purposes because it's generally considered bad for the environment to vent fuel vapors into the air.

On a USDM OBD2 ECU, it will usually throw a P1456 or P1457 code if it's missing or functioning incorrectly. You may also notice an increased risk of overflowing the tank on fillups.