I seem to have lost some get up and go in the ol' tracker. when it idles every now and then it will miss. it will do the same thing if you hold thr throttle around 2000 rpms. the 400 code keeps coming up and i've done everything i can think of to clean it. taken off the tube, the valve and jammed a coat hanger in places i didn't even know existed!  I also have a bad 02 sensor (after cat) or where the cat should be...... does anybody think one problem leads to the other? also...will the 02 sensors work correctly without the cat? I have checked my timing several times and its all good. a few months ago i had the broken crank key blues and fixed it. it ran AWESOME after that but seemed to have slowy lost some power. i have even taken out the #1 plug to make sure the piston is in the correct posision in aspect to timing marks and distributor positions. any help, hints or tricks would be appreciated thanks,                        GEO JOE

code 400 is gone now. guy at local muffler shop said to put in an anti plug fouler to cut down the flow on o2 sensor and that shoul keep the check engine light off

That'll work OK if you don't have to pass inspection. The front O2 sensor will work OK without a cat but the rear is there to check the cat is operating correctly. Without it you will get the CEL light showing. The EGR problem may be caused by a lack of backpressure in the exhaust. If the ECU doesn't see the correct pressure change in the inlet manifold when it opens the EGR then it will flag an error.