Cutting the cats off??

[ant_tundra]

I was talking to a guy @ a local performance shop and ask him what can I do to get a LIL more performance out of my 5.7,, He said cut the converters off..
Humm ok so If I do cut them and build a costume exhaust with welded o2 bungs
for the o2 sensors...do you guys think I'll throw a cel SES...

[TexBiker]

Originally Posted by ant_tundra

If I do cut them and build a costume exhaust with welded o2 bungs
for the o2 sensors...do you guys think I'll throw a cel SES...

Almost certainly...

[pullthis]

you can remove the rear 2 cats without a cel.

[Griffin]

I cant see it being really worth the effort.

But, whatever floats your boat.

[RunItHard]

Originally Posted by ant_tundra

I was talking to a guy @ a local performance shop and ask him what can I do to get a LIL more performance out of my 5.7,, He said cut the converters off..
Humm ok so If I do cut them and build a costume exhaust with welded o2 bungs
for the o2 sensors...do you guys think I'll throw a cel SES...

Not only will you do that, you won't get a smog cert which is required in most states to renew your registration.

[jpnca]

I havent looked but if the cat bolts on and off it can be replaced for smog

[ant_tundra]

Ya That's what I was thinking!!! when smog test comes around just install stock sys... So how many cat and o2 sensors are they...

Originally Posted by jpnca

I havent looked but if the cat bolts on and off it can be replaced for smog

[ant_tundra]

Nutin a LIL Spark Plug Non Fouler won't fix... On my evo_9 when I removed the cat all I did was install 2 Spark Plug Non Foulers...

Originally Posted by TexBiker

Almost certainly...

[phobos512]

There are O2 sensor simulators that people use when the cats are removed. And since it's California you don't have to get smogged for 6 years on a new vehicle. However in So Cal there are portable smog stations that sit by the highways and monitor your exhaust gasses, so you could still get nabbed by one of those.

[ProCharger]

Originally Posted by phobos512

There are O2 sensor simulators that people use when the cats are removed. And since it's California you don't have to get smogged for 6 years on a new vehicle. However in So Cal there are portable smog stations that sit by the highways and monitor your exhaust gasses, so you could still get nabbed by one of those.

As he said, o2 simulators would work. Lots of tuners use them when they remove the cat's and want to keep from throwing a code. Basically what it does is sends a false signal to the vehicle saying all things are good. I haven't looked at the exhaust very closely on our trucks but if there are no pre-cat o2 sensors this option should be avoided as there would be no data for the trucks fuel trim besides what the dummy sensor is sending which would be nothing realtime. You still need pre-cat o2's either way.

[TundraCA]

Originally Posted by ProCharger

As he said, o2 simulators would work. Lots of tuners use them when they remove the cat's and want to keep from throwing a code. Basically what it does is sends a false signal to the vehicle saying all things are good. I haven't looked at the exhaust very closely on our trucks but if there are no pre-cat o2 sensors this option should be avoided as there would be no data for the trucks fuel trim besides what the dummy sensor is sending which would be nothing realtime. You still need pre-cat o2's either way.

We have two sets of cats on these trucks. If I remember correctly, the O2 sensors are behind the first set of cats, not the second set.

I don't see a problem (i.e. throwing codes) from removing the last set of cats. However, as others have mentioned, you may not pass a smog test . . . visual and/or the sniffer test.

[notevenclose]

Let us know if this works out!