1st pre-cat honeycomb is cracked
 

I have an 88 fc vert, with the original factory exhaust system no mods. The 2nd pre-cat and main catalytic converters look like they are ok, no cracking or crud in the honeycomb that I can see.

The cracking on the 1st pre-cat is through the entire converter, and the engine side is caked with crud, and the down stream side looks to have some fiber-mesh coming out of it.

I looked at rockauto offerings, and it seemed like the catalog had the same parts listed for the NA as the turbocharged, I believe there is a difference between the two models. Maybe I didn't look close enough and they have a 1st pre-cat listed for sale that is specifically for the NA vert? Does anyone have recommendations for a manufacturer of that part?

Should I just replace all of the catalytic system? The thing is that I don't need smog testing for the 88 here in TX because its a classic. Also, when I drive around the exhaust smells fine after the startup burnoff.

If the engine backpressure is sensed off of the main cat, could the 1st pre-cat affect the opening of the 5th and 6th ports?

welcome to the board. :)

you could replace it if that's the route you want to take. the parts between the N/A and T2 are likely different, but you can confirm that fairly easily by checking the part numbers at Mazda or Mazdatrix.

however, you could also run an RB system that deletes the cats, but retains the backpressure tube to keep the auxiliary ports functional.

i suppose yet another option could be simply removing it and hollowing it out completely.

your choice.