Chevy & GMC Vans

These sensors are chain connected one effecting others.Fuel curve,advance of timing,etc.So no that isn't a good idea.

Thanks Gary, I forgot about the sensors!

I don't think that's a good idea for a long term solution. Yes, you'll relieve some of the back-pressure, but you're still forcing the exhaust, which normally goes through a 2" opening, to exit through a 3/4" opening instead. Plus, without feedback from the sensor, the engine is gonna run like crap and it's end up costing you more in fuel anyway. It's gonna stink and possibly make a racket too.

djdawg wrote:When you say "before" the cat, are you talking towards the front of the vehicle of towards the rear?

Upstream. If you open it up after the blockage, it's not gonna do ya much good, is it?