I have a rebuilt Saturn Sl2 dual over head cam engine, ALL new componets that comes up with a oxygen senor code too lean (new larger intake and race headers) bank 1 senor 1. Both senors were bought from 2 different places. which senor is Bank 1 senor 1???Thanks
Engine: 1.7 Dual over head
keep resetting codes since April
Hello I will help you with your question,
You only have one bank on your engine and the #1 O2 sensor is the one at the junction of the exhaust manifold closest to the engine.
If you have vacuum leaks on the intake or exhaust leaks you will get this code.
It may be that the sensor needs to be replaced but if more oxygen ends up in the exhaust from the modifications you have made you will have a tough time stopping the code from setting.
Let me know what I can do to help you with this
ASE Master Tech 15+ Years