As much as I hate to admit it. I think I would go OEM too.
I just replaced a front O2, that I had replaced two years ago with a after market, with a new OEM unit.
195k, 5/20/12 new ej257 short block, 8/20/11 installed VF52 turbo, @20.8psi, 280whp, 300ftlbs. CHECK your oil, these cars use it.
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