I think your right Id ask shaun at TS to make sure ...^will the 02 sim set the ready moniters also i pmed you last week dont know if you got it or you just didnt care for polocks lol. on subarus the sim will keep the cel off but the ecu wont ready the o2 moniter but them ecus are very picky
magnaflow makes a aftermarket header , should be oem replacement no 02 sim needed ....Got a question, is there any aftermarket headers that don't throw the CEL? Reason for me asking is my o2 sensor just went bad in my stock headers. I tried replacing the o2 sensor but I can only turn it a half turn and it is so tight, I was afraid I was going to snap it off. I heated it up twice and still couldn't get it loose even with a breaker bar. So in case I do snap the o2 sensor in the stock header I want an aftermarket one that won't trip the CEL.