RawDawg

I've been getting this code for about 3 months now. It only has 86000 miles on it so i figured it was time to change the primary sensors. I did all the reasearch and picked up the bosch 13111s. Codes went away for a week now they are back. I replaced both precat o2s. My car is running really rich right now and misfires. Could these o2s have gone bad already?? I read other threads and checked the engine fuse under the hood and that was fine. I've run the seafoam through it twice. I replaced the paper filter with a K&N for better flow.......I'm running out of ideas here. Can someone please help me out??!! My car isn't running as good as I know it should cause of this .....and its killin me!!

P.S.
I'm not running long tubes yet...so were the 13111s a bad idea??!!