Mazda Repair: Mazda exhaust, catalytic convertor, mazda b3000

Question
I have a 1996 Mazda B3000 pickup.  diagnostics said to replace EGR valve.  Did that.  (was also done just 3 years (30,000) miles ago) Now shows blockage in exhaust.  Should we replace the catalytic convertor with orginal parts or universal or just put on straight exhaust pipe?  The vehicle have 110,000 miles on it. Thanks.

Answer
replace with original parts if you straight pipe it you could loose all of the backpressuer in the exhaust sys causing your pcm to think the EGR valve is malfunctioning affecting your vehicles overall performance and universal parts might have a similar effect on the EGR valve