Remove Catalytic Converter for Better MPG?

[Stepperado]

So I just found out that in NC I do not have to have an emmisions inspection for my completely stock 84 (305 v8, single exhaust) truck. Since I'd like to squeek every bit of mileage I can out of a gallon of gas I was thinking about removing the catalytic converter so it can breath easier.

Has anyone taken a completely stock engine and checked the difference in mileage before and after removing a cat? Any adverse side effects from removing it? I obviously don't want to bother crawling under the truck if it won't help.

Thanks,
Stepperado

 

[DoubleDingo]

I haven't, but I am sure somebody on here has.

 

[MrMarty51]

My 93 K1500 and 260,000+ miles and it gets eighteen, with a straight through glass pack and the original convertor and 3" piping, I have not heard of anyone getting any better from these vintage pickumups with or without a convertor and or muffler.
Of course these are TBI engines but, I still have not heard of anyone getting any better mileage without the convertor.

 

[72chevy2door]

On my 88 burban I got two to three miles more a gallon better. But I also did true duals with flowmaster 40 series 2 1/2" all the way back. So it wasn't restrictive to my 350.

 

[bucket]

IMHO, the only good place for a pellet style converter is the scrapyard.

 

[firebane]

I heard that back pressure can = more mileage.. This is why running mufflers can actually be better than not on vehicles.

 

[Stepperado]

I'll tell you what, I will take a dead stock 305 with factory style single exhaust and remove just the catalytic converter and no other changes. I'll figure this out and the we will all know! I can't get to it for a few weeks, but in the mean time I can get a solid average on the present mileage so the data is actually meaningful.

Then, I will take off the original smog pump/equipment to see what affect that has on mileage.

Finally, I will add a free flowing dual exhaust and check for improvements.

Hopefully all this will be done before gas prices recover to their previous level!

Stepperado

 

[scottybaccus]

Since honeycomb converters have been introduced, they have caused little restriction, unless clogged due to some kind of issue. The newest generation is better than ever.

 

[bucket]

Since honeycomb converters have been introduced, they have caused little restriction, unless clogged due to some kind of issue. The newest generation is better than ever.

True, but the converter in question is the old pellet type. Well, assuming. The OP said the truck was all stock and that's what GM still used on the trucks then.