Have you tried going to
http://rpmfusion.org/ and downloading the kmod-nvidia directly? That's what I did to get my system going when it failed for me. Also, try uninstalling and reinstalling akmods. That may help.# rpm -qa | grep nvidia
xorg-x11-drv-nvidia-libs-290.10-1.fc16.x86_64
kmod-nvidia-3.3.0-4.fc16.x86_64-290.10-2.fc16.2.x86_64
kmod-nvidia-290.10-2.fc16.2.x86_64
nvidia-xconfig-1.0-11.fc16.x86_64
xorg-x11-drv-nvidia-libs-290.10-1.fc16.i686
akmod-nvidia-290.10-2.fc16.2.x86_64
xorg-x11-drv-nvidia-290.10-1.fc16.x86_64
nvidia-settings-1.0-13.fc16.x86_64
# rpm -qa |grep akmod
akmod-nvidia-290.10-2.fc16.2.x86_64
akmods-0.3.8-3.fc16.noarch
These are the latest under RPM Fusion (Fedora - nonfree) 16 (x86_64)updates listing:
2012-03-22: akmod-nvidia-290.10-2.fc16.2
2012-03-22: kmod-nvidia-290.10-2.fc16.2
2012-03-22: kmod-nvidia-3.3.0-4.fc16.x86_64-290.10-2.fc16.2
Edit: Congratulations Bob. Unfortunately, I can't help you with the catalytic converter. My sympathies.