I recently bought some stone headers for my car which is a 01 Acura CL-S. I noticed that I have the whistle sounds...it range from about 2.5k - 5k rpm, also my check engine light is on due to the O2 sensor... anyone has the same problem ??? Should I replace the o2 sensor or just clean it with methol.

Thanks

 

Sounds like you blew the O2 sensor during install...You probably need to replace it.

Also, I believe that Stone headers have that resonance problem in the RPM range you described. It's "normal" for those headers

Have fun !!

 

Yep, the shop that did the install probably damaged the O2 sensor. Also the whistle noise is either resonance or maybe a warped flange is preventing a tight seal somewhere.