I just got me a 2004 Mustang Gt 4.6L and the guy I got it from put on long tube headers and Borla exhaust. The service engine light is on, it reads P0153 Bank 2 Sensor 1 - O2 sensor Circuit Slow Response. He said it had this code because of the long tube heads, which makes sense. Well a few days ago I decided to hook up my OBDII scanner and now it gives me that P0153 code I previously mentioned but it also gave me a code and I believe it said the Bank 2 Sensor 1 O2 sensor is stuck and another code saying Bank 2 Sensor 1 O2 sensor is running lean. I'm just wanting to know if the o2 sensor is actually the problem or is something else causing those codes? Maybe a vacuum leak or maybe it needs tuned. I'm on a budget and don't want to waste money on a new O2 sensor if that isn't the problem is all lol. Thanks.