Hello everyone, I have a 2006 Hyundai Elantra that is giving me a CEL with code p2237. The code is for the O2 sensor bank 1 sensor 1. I have already replaced the O2 sensor and cleared the code and a couple days later the code came back. Does anyone know what else it may be that is causing the code?

 

If I suggested that you check the o2 sensor heater circuit,what would you do? If you don't have the equip and knowledge to do this , best to have a good shop check the vehicle.

 

There's a high chance your exhaust gasket is done and need replacement or you got an exhaust leak before the sensor. One way I try to look is to get a leaf blower and stick it into the exhaust tail pipe and spray the exhaust manifold with soapy water and see if there's any bubbles around while you got the leaf blower on

 

That is a cool idea for finding an exhaust leak.

From the code you mentioned, I believe it suggests checking the oxygen sensor heater circuit.