so I bought a 06 MR and it's been tuned, i need to know how many o2 sensors are on there and how to turn them back on. The mods that are on it are aem intake, tanabe downpipe, had a test pipe on but put the stock cat back on, HKS hi power exhaust, boost pill, lower intercooler pipe, and tuned by bryan at GST. i can't finish smog because it keeps saying the o2 sensor isn't ready.

 

There are 2 of them. One in the o2 housing after the turbo, and one farther back in the exhaust near the cat.

 

The o2 sensor would have to be turned back on via ecu flash...through periphery bits...