Denso Oxygen (O2) Sensor - 234-4445 (Fits Select Years of Subaru: Forester/Impreza/Legacy/Outback and Saab 9-2X Vehicles)

Fit my 2009 Forester non turbo perfectly. The length was exactly like the original and even had the original style lead clip.

Perfect fit!! Easy to install once old one is removed. Special removal tool is helpful.... I used the "Aoerzn Premium Offset Oxygen Sensor Socket, 3/8-Inch Drive, 7/8-Inch (22mm)". Worked great. Came with original Denso box (see pic) and enough copper anti-seize to do 3-4 sensors. This is the EXACT part you would get from AutoZone. I know because I bought one there too because Amazon was super late in delivering and I needed to get it done. Our car was throwing a P0031 code. I replaced BOTH sensors (which is recommended). Other sensor was a 234-9123. Soooo glad I replaced both because the car is more zippy now. Note: Be careful removing the old sensor. If it won't budge, the pipe may needed to be heated to a cherry red with a torch. PS... If you find this comment helpful, please hit the "helpful" icon. Thx! 🙂

I own a 2008 5MT Outback with over 200k. The car has been fantastic. For the last couple years I've been getting a random "Catalyzer below threshold" code. I thought it was time to replace the cat converter (not surprising giving the miles). But I decided to try the anti fouler bung on the O2 sensor. It worked for a while, but my check engine light kept coming back while in the highway, disabling my cruise control (some "lean condition" code. On these Subarus, and many newer cars, the downstream sensor (after the converter), is not only to check the efficiency of the converter but also has something to do with the fuel trim). I finally decided to replace both O2 sensors (the car well deserves new sensors after all these years), and sure enough, the check engine light has not returned, engine runs smoother, and I should expect some improvement in the fuel mileage. So, if you're on the same boat, replacing both O2 sensors quite probably will do the trick, and it's way cheaper than the catalytic converter. One last thing....as many people before me pointed out...don't use cheaper sensors. These Denso ones are OEM, and work fine.

Perfect fit and replacement of OEM part of a 2006 Forester X, including the wire plug, wire clip, and even the insulation color. Includes way more than enough anti seize grease. The car has been throwing occasional check engine light codes about the catalyst being below efficiency threshold. More recently, it threw a new one about running too rich. I replaced both sensors. They had 180,000 miles on them. Hopefully, this should fix things. These tend to last a long time, but not forever. This can be done under the hood if you are a bit of a contortionist. A 22mm or 7/8" open end wrench will sometimes get it, but mine was too tight. There wasn't enough room to get the wrench on it where I could apply much torque at all. Got a split crow's foot style socket (don't think a straight socket will fit with this car), and a long extension bar. I had to remove the air filter box, a simple thing, to get the bar in the right place. Once it broke loose, I was able to finish by hand. Don't over tighten. It only needs about 15 foot pounds, about what a spark plug needs. Get it too tight, and it'll be a BEAR next time.

Installed this on my 2006 Subaru Forester as a best guess to try and fix OBD code P0420 and it worked! Since the original O2 sensor made it to 180,000 miles, I can't complain. This sensor did not have anti-seize installed or with a packet and the packaging was pretty beat up, but it went in without a hitch and the connector matched exactly. Been 500 miles and no code yet so all is well. Had a hell of a time getting the old one off until I bought this: ABN 3 Piece 3/8" Drive Oxygen Sensor Wrench Socket Set

Bought this after getting a sensor code and check engine light coming on with the other usual Subaru lights flashing. Bank 1 Sensor 1. Decided to get this specific sensor after watching some videos recommending this brand. Comes with anti seize already on the threads. Great quality and perfect replacement for 2011 2.5 outback limited. Easy to install, do yourself a favor and use an open ended wrench, don’t bother with the sensor wrench it just doesn’t fit in the space you have between the radiator and converter. Gas mileage improved by 4mpg highway. No more engine light. Happy I bought it.

still looks new, performs like new. still had anti sieze applied and the tube of extra was with it. OEM sensor, saved $20+ and my Impreza now has no lights on the dash at 180k. Don't listen to the people who say buy a catalytic converter first. 🙌🏻

Crowfoot wrench is the way to go.

Fits to my Forester 2009 like original part. Come with copper grease with original Denso box. No issues et all during the installations was happened.

its only work 1 year then have a same issues with the same code reading bought it last year so disappointed with it

Works perfectly with my 06 Subaru Impreza. Was able to replace my old ones with these in 15 minutes. Easy

Easy to replace on my 2009 Subaru Impreza, and the car runs great again.

OEM quality, fit and finish