The cheap replacement o2 sensors appear to have a hit or mis build quality. Another thing that will kill the sensor is anti-sieze. If the anti-sieze contaminates the sensor, then it will malfunction pretty quickly and fail.

 

Thanks for your thoughts, i will just order an OEM mitsu one i guess.

 

https://www.evolutionm.net/forums/ev...version-4.html
Scroll down to see pics of OEM vs. DENSO

Denso 234-4741
$63 from Advance Auto

Direct plug-n-play and works like a champ.

 

I called my misti dealer for a quote on a front O2 sensor, part only was 699 plus tax. I got an oem walker one from oxygensensors.com for just over 100 including shipping, 20k km on it so far no problems. (NZ market obviously).

If you do get an oem one from Mitsi, let me know how much it was.

 

This is the one i just ordered and installed its a pile of crap.

 

Usually the OEM mitsu ones are 300 ish

If you have an friend at the dealer they can get them at employee discount for about 210-220

 

What qualifies it as a POC? I have been running mine for 10 months with no issue. It is the OEM Denso replacement for another mitsubishi vehicle.

 

The Ecu is giving me a P0133 '02 sensor slow response code' and the AFRs are all over the place,,, Swapped in a known working OEM Evo 02 sensor to verify, no codes, no afr issues,, I also noticed the Tip of this 02 sensor has different holes in it then the factory unit, its probably not truly identical...

Ive had two other friends in town order this denso unit, and i put one in an Evo8 a few years ago, all of them worked fine, i must have just gotton a DUD.

 

I have used chain auto part stores replacement plug and play sensors in 2 EVO's and both never had any issue.

You may have very well have gotten a bad sensor.

 

Rock auto is a great place for cheap OEM replacements. I got my front O2 sensor for around 59$ and it was direct plug and play. It was either Bosch or denso and I haven't had any problem with it.

 

seems like NO complaints from anyone on here for the BOSCH + it comes with 1 year warranty. So i guess BOUSCH universal it is

 

yeah the price difference is crazy thats why i am leaning to the universal