Whats a good High flow cat for my 300 6 cylinder. There is two cats on there now and I would like to remove them and put one on. Will one cat still pass the smog test?

 

You might want to be careful there. Technically your not supposed to mess with the cats. Look at the specs of the new cat to see if it can do the job of two. I've replaced my own cat with a high flow one from Bassani. But be warned they ain't cheap, around 325.00. They bolt directly to the headers.

 

THe stock front cat is nothing but a resonating chamber to preheat the exhaust gasses, while the second is the actual cat. Any 3-way cat with an air tube will effectively replace the original units.

For legalities, it depends on your location. I know in some places they do a visual inspection, and if you had 2 cat's stock and only a single now they'll fail you, even if you pass the sniffer test.

TrailDawg
https://www.ford-trucks.com/dcforum/User_files/3aaa4bac6f539876.jpg
1993 F150 2WD
6" Lift w/35's
And STILL waiting to get my 4.30 gears installed!!!!
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