I don't have a modded Ecu and I needed to replace the both O2's. I went to Advance auto parts and got 2 Bosch for like 14 bucks. I got the kind that you wire in. Then I wired them in. I've been running 2 days and everything is fine. So if you want to replace the O2's ask for 2 (1.5 sohc) that need to wired in. They work just fine. I don't have part number but they keep them in stock. Tested and proven. For those of you wondering about the wierd A/F reading it didn't fix that issue. Where it dissappears and then comes back. It's not fixed. Still working on that issue.