Denso 234-9123 Oxygen Sensor (Air And Fuel Ratio Sensor), Regular (2349123)

I installed this sensor on my Subaru as part of regular maintenance. Since it is OEM, it fit perfectly, and the cable clips were in exactly the right spots. It has performed with no problems.

I bought this as an upstream sensor for 2007 Subaru with a 2.5 liter engine to replace an original after 225,000 miles. It came with some copper anti-seize compound. It looked like the original with one important exception-the wire connector was different than the original one in my car. I checked the part number several times, and even ordered another one from my local parts store to check it-the numbers match but the connector is different. Perhaps there was a change made after my car was made. Because I needed to get my car back together, I cut the connectors off and swapped my original onto the new sensor-the wires are the same, so it was just a minor challenge, but cutting into an expensive part made me nervous. The sensor has worked well-no check engine light, and the scanner showed fast response and good fuel trims.After almost 6 months and more than 10,000 miles, this is still working. There have been no error codes, fuel mileage is what I would expect and the engine runs great.Update. Almost 2 years later the engine is still running strong, good fuel trim, no sensor-related check engine light.Update. I got another one of these for another car, and in the process learned why I thought the connector was wrong. It has a plastic protective piece that I thought was part of the connector itself. Removal of the piece revealed the correct connector. That was a critical thinking problem on my part, and realizing the error of my ways has hopefully made me a better person in some small way.

it fit perfectly as far as the connector was identical oem. you want to only go with denso which is the oem supplier for subaru. price from this vendor is great, best i have seen anywhere. new at oreilly etc was $50 more cost! ck engine lite went out immed, car runs so much better as this going bad really messes up the fuel mixture- makes car run rich, so gas mileage is better and it runs way better, more power etc. this is the upstream 02 sensor, which is the one that takes the worst beating of the two 02 sensors in any vehicle. it should be replaced about every 80k miles, the downstream one can go longer. funny but my ck engine lights just got thrown, runs fine but something threw that, could be downstream sensor but car only has 90k miles so it should not be going bad this soon. supposed to go like 150k or more even because its downstream of the catalytic converter so it gets cleaner air and doesnt go down as fast as upstream which gets raw untreated exhaust. i did a ohm test on downstream and it was in spec, i did upstream prior to replacement and it was showing out of spec. ck engine analysis cemented the fact it needed replacement at about 90k mi, but actually the lite was throwing at about 84k. newer subarus are more sensitive to sensors, mine is a 2010. 2008 and older are not nearly as effected by sensor health as 2009 and newer.

If you have a Subaru that needs a new air fuel sensor or front oxygen sensor this would be the one to go for this will turn your engine light off as long as the sensors the issue unlike the Chinese replacement sensors which will give you issues with the heater circuit worth the price cuz they actually work do yourself a favor if you're going to replace your sensor do it with a Denso on a Subaru

Direct replacement for 2006 Impreza (and many other models and years). First one leaked air through the stem right out of the box. Amazon took the return no problem.Some installation tips: getting the old one out is the hardest part. They often get really baked in there. Removing the headers isn't that hard, so if an offset O2 sensor socket doesn't break it loose pretty easily, just pull the headers. If the old one comes out easily then this one should go in easily. If the old one needed a lot of persuasion, it would be smart to get a thread chaser and clean out the female threads before trying to thread this one in.Once it's installed, tape a shop vac hose on "blow" into the tailpipe to build up a little pressure in the system and spray any joints you messed with (o2 sensors, headers) with soapy water. Bubbles = leaks.

This is what subaru uses in their cars aftermarket parts that are cheaper don't usually work properly in a subaru or they work temporarily and you end up buying the original part. Still 50 to 60 dollars cheaper than buying locally for the same part

Car started throwing 420 cat converter code, which this solved immediately. This was very easy to swap out, literally unplug and unscrew old sensor, and plug in new one.

While the aftermarket does provide a good amount of products as replacement parts. There are still some area’s that the OEM replacement parts are the only choice to use. This comes from personal experience in the automotive industry as a mechanic.

Le quedó de maravilla a mi camioneta y la misma marca y el mismo modelo funcionó correctamente.

Replaced the front A/F sensor with this OEM part, fit perfectly and works perfectly, spend the extra to have a quality name brand, I had previously purchased a non name brand, trying to save some cash, it lasted 1 week, it looked the same until I actually measured the 2 sensors, the no name was actually longer, and the car kept throwing codes, once replaced with the Denso sensor, no more codes

i’m not recommendedit’s doesn’t workbought it last yearand now have same issuesso disappointedcheers

Great product/quality price - prompt shipping

Exact replacement fit perfectly and no issues once installed.