the first o2 tells if your lean or not the second o2 just checks to make sure the cat is working correctly i think..

 

Well unless I'm wrong, when our cars get any CEL the ecu will go into "limp" mode and will run lean to avoid furthur problems.

Somoene correct me if I'm wrong.

 

No, not "any" CEL will cause "limp" mode, only some CEL's.

Not having the 2nd o2 sensor will trigger a CEL, but not "limp mode".

Check/replace the PCV valve. You're probably loosing oil from the top of the valve train into your intake manifold, then into the cylinders...

 

Having a faulty second 02 sensor, or having it disconnect WILL make your car run like ass though..

Try it...

 

I want to purchase an safc2 and tune it. What searching I've done so far shows that I'm going to have to reset the ECU every so often ( meaning what exactly? every month? ) so that it doesn't bypass the safc2 and run its own numbers.

Only problem is there is no dyno shop around here so It would have to be a butt dyno on a empty highway at WOT.

Before I pruchase this can anyone give me pointers/heads up or teach me what else I need with the safc2 to run everything well or is it a waste of money?

I got cai, bbtb, ported IM, ngk plugs and wires, headers, exhaust.

 

does the car smoke at all or at least upon start up


my celica smoke upon startup but its due to the vavle stem seals have gone bad

 

Nope. No smoke.

 

^^^ if you have catalytic, there may be no smoke from oil at all

see if you have oil in the air filter pipe near the throttle body.

 

Which line? The one connected to the elbow? Or the one connected to the IM