Which is Better?

[ht89]

I'm currently planing out the exhaust system in a 94 SCSB with an 07-08 5.3 / LY5. I've narrowed my options as follows:

1. A long tube set up with a 3" Y pipe and a single muffler. My local jurisdiction does not have smog check restrictions so I'm thinking I'd go with out cc and a single 02 sensor. If a cat every became necessary it could easily be added latter. I figure this set up would closely copy the 1994 stock configuration.
2. If the long tubes in the 1st pic won't fit then I'll go with shorties a cc Y pipe. The Y pipe is 3" diameter with "high flow" cats. I figure this set up would closely copy the 2007 stock configuration.

My questions to the community are:

• Does an LS swap need catalytic converters?
• Can an LS swap use a single 02 sensor?
• When I send the ECM out for Pass Key, Variable Vale Timing and Displacement On Demand deletion, do the number of 02 sensors and catalytic converters also need to be reprogramed/deprogramed?

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[Schurkey]

1. Emissions-control equipment is FEDERAL law, it may or may not also be State law. Deleting emissions control equipment is illegal anywhere in the USA. Whether you'll get caught is another thing.
2. I'd expect that pre- and post-catalyst O2 sensors will be required. Likely two in front of the cat(s) and one behind each cat.
3. You'll likely have to have the cat(s) in the original location. Given that this is an engine-swap deal, I don't know if that's the original location for the vehicle, or for the vehicle the engine came from.

What can be removed in the "tune" will depend on who's doing the programming.

You ought to check the Federal regulations. Perhaps you'll still choose to delete stuff, but at least you'll know what it'll take to achieve compliance if it ever became necessary.

 

[Edward Case]

The maximum federal fine for tampering with emissions equipment is only $45,268.

 

[letitsnow]

I think that most end up with an o2 sensor on each side about a foot past where the oem exhaust manifolds would end. You then have to tell your tuner that the truck is only driven offroad, so they will tune out the rear o2 sensors.

It might depend on what you are using for a wiring harness?

 

[OutlawDrifter]

You will have to have two 02 sensors, one for each bank. The rear 02's can be deleted.

Unless you have some serious mods done to the engine, you won't be able to tell the difference between a long tub or short tube setup.