Minnesota Focus Owners Club

Since Starconvoy and I installed the header, I'm getting trouble codes P2196 (Oxygen sensor or Air/fuel sensor stuck rich) and P0420 (Catalyst efficiency low). The one common troubleshooting thing between these codes is "large vacuum leak". I checked for those and made sure the PCV was in its socket. Any other tips or people that have had similar problems?

dartfork wrote:Since Starconvoy and I installed the header, I'm getting trouble codes P2196 (Oxygen sensor or Air/fuel sensor stuck rich) and P0420 (Catalyst efficiency low). The one common troubleshooting thing between these codes is "large vacuum leak". I checked for those and made sure the PCV was in its socket. Any other tips or people that have had similar problems?

Long tube or short? New O2 sensors or no?

sounds like a dead 02. its possible it was damaged during install.

Short tube header. We didn't replace anything but the manifold gasket. So the O2 sensors are old too. Though we were pretty careful not to wreck them. How fragile are they?

dartfork wrote:Short tube header. We didn't replace anything but the manifold gasket. So the O2 sensors are old too. Though we were pretty careful not to wreck them. How fragile are they?

still have the stock cat? chances are its broke apart. it happens when you change the exhaust system, its caused by a rich/lean condition the cat just starts to crumble. empty the cat out and replace the sensors.