i just installed my oem cat on my 4in turbo back, noticed much more backpressure cant tell if any mpg have changed just yet and egt are the same driving and romping in the streets. performance wise i can still feel the power but kinda feels a tad bit restricted possibly a slight hp loss. exhaust sound at idle is less and doesnt stink anymore and when you romp on it it still gets loud and can still hear my powermax spool.

anyone running a cat with bigger injectors ?

reason for cat being installed is so i dont get a fat fine if i get pulled over..

 

Empty the guts out of it so it visually appears to be intact.

 

well, used cats are worth money, that's why the folks
cut them out of cars in the parking lot....

we used to clean them out to fake out the smog *****,
and probably the safest way to do so, is to take and soak
the cat in a bucket of water so it's completely immersed,
and use a long drift and a single jack to break out the
insides.

don't try to remove the insides dry. very toxic.

i've got a 95 trans am with a LT-1 in it, and i put on a
high performance cat that is smog legal, and no
back pressure to speak of....

is there anything like that available for diesels?

funny thing, last year in calif. i got smogged on the
van, and this year, i also got a smog notice... two
years in a row.

last year, the guy started it up, blipped the throttle,
looked in the mirror at the exhaust, said... "good,
no smoke" and passed it with a visual.

we shall see what this year brings.

something i did find that was interesting, i have
a couple quarts of ethos FR+ that i ended up
trying a while back.... and the stuff doesn't change
the milage at all... however, what it does do, is
almost completely eliminate smoke in the exhaust.

so, i keep it for "smog day". time to fill up the tank,
and put 4 oz. of the stuff in. you can bury your foot
in it at night, and look back to see how much smoke
you have in the headlights behind you, and not see any.

we shall see what this years smog test looks like....

 

I you don't tow & don't use an extreme tune, your egt's will be ok. I lost 200-300 degree's after my kitty fell off.

 

Something is wrong with my truck then cause with a race tune I'm hitting 1250 WOT

 

Not shure about that, with the extreme race tune & 40 hp ficm tune im way above that number...

 

With a fuel system a powermax stock sticks x race and 40 ficm I can't get over 1250 dfuser tune hits 1250 as well, looney wild hits 1350-1400 and with the cat on it didn't change my egt at all even at fwy speeds of 75mph

 

That's a good thing! You could leave the cat on, if you dont like the sound without it. Maybe my 8200 lb excursion's weight has mine close to 1500 degree's! Or the fact it happens over 100 mph.

 

No problems here. 155 injectors and the cat is just humming along.

 

That's not true. I tow ~16k a lot and my EGTs are nothing to be worried about unless I make them something to be worried about. I can peg out my 1500°F EGT gauge in 5 seconds if I wanted. Hauling above mentioned weight and I'll see about 800°F degrees. Climbing a 3% hill, around 1100°F on the pyro.