AF & O2 Sensors for a Subaru

[Zedlum]

I'm having issues with a Subaru Forester 2009 N/A running a liquid injection LPG system. It appears to be wandering rich over time and slowly getting right out of tune. After around four months of trips back to the installer and importer trouble shooting the system it appears that the problem might be with the cars engine management system, specifically the precat AF sensor. I have found suitable Bosch and Walker replacement parts, the original is a Denso which is poisonously dear here in Australia. Both Bosch and Walker claim OEM or better quality... anyway, I read that AEM senors are better so my question is can I replace my pre & post cat sensors with AEM units and if so what advantage do they offer me?

[specialed]

The AEM sensor is calibrated to work with the AEM controller. It will not work as a direct replacement for your factory sensor. The AEM UEGO would work as an independent O2 system. You would not want to place the sensor post cat as the readings could be affected, pre cat is where it should be placed.

[Zedlum]

Thanks!