One or two O2 Sensors ST's only pls, I want to find out if I can convert my Celica to Fed spec. Options

[bindertch]

I was wondering because I am in the "has a header and a check engine light group" because I removed my front cat and do not have the rear O2 sensor hooked up. If I buy an ecu from a Fed spec 7AFE would it still need the rear O2 sensor? This is so that I don't have to modify my exhaust yet. A waste till I save for the 2" pipes that I want.

[bindertch]

also, there is no federal emission 7afe, they are all (94-97 7afe) cali spec.

Are you sure of this?
And about the bung I would have to have it welded after the cat that I have and then hope that it still doesn't set the CEL off. Being that it isn't really nessesary Iwould rather do without.

[Batman722]

also, there is no federal emission 7afe, they are all (94-97 7afe) cali spec.

Are you sure of this?
And about the bung I would have to have it welded after the cat that I have and then hope that it still doesn't set the CEL off. Being that it isn't really nessesary Iwould rather do without.

yes I am sure. All 94-97 ST USDM Celicas have 2 02 sensors, and they are both nessessary. If you do not have your second 02 hooked up then your mileage is probably gonna be messed up and the car won't be running as well as it should be.

Just have the 02 flange welded in about the same spot as where it is with the stock pipe. I don't understand why you are trying to "cut corners" with doing this properly...