Suggestions Needed

[ChickenRammit]

I Just Installed A '96 5.7 Vortec Engine Into My '86 K5. The Vortec Has 4 Oxygen Sensors(2 Before The Cat And 2 After The Cat). The Donor Vehicle Had 2 Cats And My Blazer Only Has One. Is There Any Way I Could Just Use One Hot And One Cold Oxygen Sensor Without Triggering A Dtc Or Do I Basically Need To Use All Four Sensors. Thanks-brian

 

[1979jimmy350]

you could either put both the post cat sensors in the same pipe of buy a o2 sim for one of them, if you already have the sensors it would be cheaper to put them both in, the only problem you might run into is for smog with changing the number of cats on the engine, if you still have the trucks exaust you might want to put bot cats on then you could run true duals

 

[Blue85]

It's going to want a good signal from all of them. The two sensors before the cats are probably setting the mixture for the right and left banks. Absolutely use those. Put one on each bank, but figure out which one goes on which. As for the O2 sensors after the cats, they are just there to make sure the cats are working right. You could replace them both with simulators, but since you already have them, just install both of them behind your one cat.

 

[ChickenRammit]

It's going to want a good signal from all of them. The two sensors before the cats are probably setting the mixture for the right and left banks. Absolutely use those. Put one on each bank, but figure out which one goes on which.

SHOULD I PUT THE TWO PRE-CAT SENSORS ON THE Y-PIPE FROM MY HEADERS? IMMEDIATELY AFTER THE Y-PIPE, MY EXHAUST IS DOWN TO ONE PIPE. IT SEEMS TO ME THAT DRILLING AND WELDING TO THE Y-PIPE MIGHT LESSEN THE PERFORMANCE OF THE HEADERS.

 

[tunedportk5]

are going to have to smog it or is it diesel?

 

[ChickenRammit]

Yeah, I Want It To Be Smog Legal