Can I put my cats directly after my LT headers or will this cause some kind of problem?

They are Pacesetter LTs, and magnaflow 59959 cats.


Could I place a single cat further down the line, where the ORY flange meets the "cat-back" flange? Would temps be hot enough here?


I need to pass a visual emission test this week, I don't mind running cats, and the dummies at the IM station will okay me so long as it looks and smells legit.

Edit: this is on a RCSB 2000 5.3, 4wd so there isn't much room for alternate placement.

 

Keep them close enough to the header so that they will light off!! Too far back and they are kinda worthless. But on the other hand.... If its jsut for visual, install it somewhere simple then take it off.

 

I just finished welding it to the flange that bolts up to the "cat-back" portion of the exhaust.

I only used one cat, and I had to cut about 1/2 inch of each end of the cat to make it fit. Before I re-installed the band clamps I fired it up. Less of a gassy smell, but I didn't run it long enough to get hot. I think I'm just going to weld up the joints where the ORY pieces together. I got small leaks from all of them when it was just clamped together.

After I pass the smog test, I'll ask another shop to sniffer me just to see the readings.

 

I got it all together. No stink, and the truck sounds much better. No rasp, and none of that bbbbrrrraaaaaattttt sound between shifts.

 

got pictures? Would love to see how they fit in there.