From time to time (now more often), in traffic, my 2002 VTECH Civic Ex does not accelerate passed 20 mph. Check engine light stays on. I connected it to the computer and results were about an oxygen sensor. Someone told me it could also be clogging in the cat. Can the oxygen sensor trigger this issue? Please help...

Thx,
Felix

Yes. Replace the proper oxygen sensor (upstream or downstream) and clear all codes. If the problem persists, you may have to replace the catalytic converter.