Folks - just in case you were considering these cats - my recommendation is not for FI.

After going through 4 of these, its time to try the 4 inch diameter diesel ones which Im told may fare much better. We started with the cat installed after the header, 1foot away, 2 feet away and 3 feet away and all have resulted in the same; Destroyed in the middle the metal becomes a ball of scrap resulting in Loss of power, higher boost due to exhaust back pressure and slower windup to 6000rpm. Of course once installed the truck wakes up but gradually goes downhill from there. In the end, just too much flow FI. I am however convinced that it should be fine for NA. The distruction ocurred mainly after several excursions to high boost.

 

Interesting sh*t.

 

you need the cats with the ceramic internals and they should not be mounted immediately aftern the collector for FI applications . I blew out my stainless works converters the first day....i replaced them with the magnaflows with ceramic internals and placed them a little farther downstream and had no issues

 

Previously I had the carsound ceramics which held up a little better. The diesel ones that Im trying next should be ceramic also.

 

I had one do pretty much the same thing, as have many others on this site. It seems to be more prevalent on an FI setup than N/A, but it also seems to be due to Air:Fuel ratio. From all the research, along with many others' opinions it appears that these absolutely HATE rich conditions, although the exact A/F ratio at which the self implode is hard to figure, there are some on here who have their tunes really dialed in and are still running these without a problem.

I know for a fact that I had an issue with mine due to a POS O2 sensor on the passenger side combined with zero tuning right after I installed my headers. Turns out the driver side was fine and stayed that way for a LONG TIME until I removed them earlier this year. False lean condition as a by-product of a random misfire caused too much fuel in the passenger bank, it was purely my fault for not doing a proper diagnosis on it and fixing it. Your condition may be different than running too rich, but this just seems to be the synopsis of the threads I have seen on these metalic wound converters.