Just installed my berk hfc's and im happy as hell...sounds awesome compared to before hand...definately pulls more and just overall feels like it runs alot smoother while at idle or driving... along with my ztube/k&n and mrev2+5/16ths im super happy...

while changing them i had trouble with the one rear 02 sensor on the passenger side due to the rust...and now its throwing a code about the self heating function or w/e...(my mechanic/neighbors scanner identified)...so basically i just need to replace that sensor and DAMN these sh*ts are pricy...i would get the cheapest one but my mechanic told me a few horror stories about the universal ones...so any recommendations about an 02 sensor thats worked for you thats like around 100 bucks?...or as cheap as possible with no issues...thx!