Do these fail often?  I R & R it when replacing intake manifold gaskets and it had a fair amount of carbon buildup so I gently scraped off most of it and I don't have a "check engine light" problem, and this car has passed smog 3 times so far. It runs good and seems to be getting OK mileage, has about 155K miles no smoke or steam coming out of exhaust, plugs look good also. This image is from a 1994 Impreza but seems to have same exact motor i.e. 1.8L H4

 

 

it goes in the threaded hole to the left of this brass stand off  (passenger side of intake manifold)

 

Thanks

Craig

 

Edited February 26, 20251 yr by Craigar

I'm away from my service manual at the moment, but I'll check it later today to see what's up with the California emissions setup.

I'd scan for codes first because that'd tell you if a sensor is sending out-of-spec values.

Under the steering column, remove the two plastic panels. The panel closest to the pedals has a metal c-clip going around the steering shaft, just force the panel downwards and it'll pop right off.

With the panels off you'll see the ECU with the three large connectors going to it. On the ECU will be a hole with a small LED inside. 

Turn the key to ON and watch the LED. Long light flashes are values of 10 short flashes are values of 1. So 2 long flashes and 4 short ones will give you a code 24, for example. There will be short pauses between codes. Let it cycle a few times to be sure you count the flashes properly.

You can look up the codes online or in a hardcopy service manual if you have one.

 

I'd imagine the EJ18 sensor you've shown above is different from the EA82 sensor. But I'm not super familiar with all the emissions hoopla you Californians have to deal with so I could be wrong. I can get you the part number for the sensors later today.

 

That EGT sensor is correct. P/N 22629AA000.

Thank You SuspiciousPizza for the update that it is also used in a California SPFI EA82

 

Yea this sensor isn't listed - or any  egt sensor - for an EA82  (at least not at RockAuto or Fleabay, google search)  nor do I see it in any of the exploded intake manifold views.. but it looks about identical to this one

https://www.rockauto.com/en/catalog/subaru,1994,impreza,1.8l+h4,1268861,exhaust+&+emission,exhaust+gas+temperature+(egt)+sensor,17051

The smog guy also showed me that the black rubber tube on the bottom of the Evap canister doesn't connect to anything - it's just dangling.. and I can't figure out where it should go , but he says that sub system tests OK so he can ignore it..?

 

Thanks again

Craig

 

Edit 1 hour later : This post says it's a dangler i.e. goes nowhere - except maybe in the hole in the frame, and I see a hole on the frame I could stick it in .. so I'll stuff it in..

https://www.ultimatesubaru.org/forum/topic/36898-quickeasy-charcoal-canister-question/#comment-297552

Edited February 27, 20251 yr by Craigar

Mine also has the "hose to nowhere". I don't know how the emissions system fully operates, other than observationally ("this hose goes there, this one is for vacuum, etc") but my guess is that it's an overflow tube. 

You're good to just stuff the hose through that hole below the headlight mount. 

 

That’s a standard tube on just about every charcoal canister. The Gen1 Liberty has the same sort of setup too. 

Did that sensor end up solving you passing your smog test @Craigar? 

Cheers 

Bennie