Which trucks came with dual cats?

[bwchevyguy]

I've owned 3 of these truck now. The '92 & '93 had larger exhaust pipes coming off the manifold into a large cat. Both were 2 wheel drive. One was a 4.3 and the other a 5.7. My '98 4 wheel drive had smaller exhaust pipes coming off the manifold into two small cats and then continues to be dual all the way to the muffler. It's a 5.7 as well. Just wondering what models/years/options had the dual cat set up. Is the dual set up better?

 

[1997chevydriver]

96+

They started coming with 2 from the factory when the put the vortec motors in

 

[MOBS]

The v8's with vortec heads had dual cats that were hi-flow. In general, the 1996+ had dual cats. The dual setup was for the change to vortec heads which are much higher flowing than the failed swirl chambered heads used with the tbi engines.

 

[LoudnLifted88]

vortec 350's only the 305's dont

 

[1997chevydriver]

vortec 350's only the 305's dont

Really?!?!?!? I did not know that! I wonder why???

 

[LoudnLifted88]

idk i know my 305 is a single 3 inch pipe from the cat back

 

[1997chevydriver]

So your truck only has 3 o2 sensors? good to know!

 

[LoudnLifted88]

i guess so only 2 are hooked up

 

[MOBS]

It may be that it was a Dixie Customs, but my old '96 with the 5.0 and 4l60e had the dual cats. It could also be depending on the state in which the vehicle was sold(due to difference in emissions reqs), that the exhaust varied.

 

[LoudnLifted88]

idk all the vortec 305's ive seen in the junkyards were single pipes i thought it was that way for all of them all the 350s around here have dual cats though