All it took for me to gut my cats was to throw in a pair of high lift cams. I went through 2 sets of cats then. All the guts just blew right out of the tailpipes. I replaced the cats with straight through Dynomax bullet race mufflers and all is good.

 

^Ditto!

 

i didnt mean it to gut cats, i simply meant it to render the cats damaged so you can legally have them replaced with hi flos. Thanks for the info.

 

Just puncture em with a rock. That happened naturally on my Saleen several times unwantingly due to the car being so dam low.

 

Thor01 is absolutely correct. Whatever you do, DO NOT attempt to break up your cat's guts and "blow them out the exhaust". You may succeed in blowing some debris out the tail pipe but you will run a very real risk of the engine sucking some of those very abrasive brick particles (like very fine sand) up into the cylinders. That's exactly what happened to me!

Not in my L, thank goodness, but in my SHO. Happened a few years ago and in my case was due to defective cats, but the principle is the same. (I was told that this was the first time this had ever happened.) It scored my cylinder walls and did other damage. Ford replaced the short block because it was still under warranty (about 30,000 miles) at a cost of over $8,000. Rather than replace the cats my tech did what Thor01 suggested and welded in a pipe, then closed up the cats. They looked stock and, because FL does not do emissions testing, I was good to go.

Mike

 

same here!!!!!!!!!!