Dual (CA) Catalytic Conversion to the Single Catalytic

[shantishunn]

I live in Southern Orgeon and recently bought a 1999 Toyota 4Runner. Everything seems to be really solid, but it needs the catalytic system replaced. Because it had been a California 4Runner, it has the Dual catalytic set-up which costs over $600 just in parts to replace it.

My curiosity is this: Can you easily convert from the dual catalytic system to the single catalytic system (less than half the price and passes testing where I live)? I ask as I have to replace it soon given it is slightly constricted and causing the engine light to come on due to the sensor past the the rear catalytic.

Any and all assistance is appreciated. This vehicle needs to be a dependable towing vehicle for our RV Trailer and this is one of the areas needing fixing. I've already put a K&N cold air intake on it, but want to get the air out flowing more smoothly.

 

[shantishunn]

Essentially i'm looking for a fix to get better air flow that will still pass OR DEQ for the next 5 years since after that it is exempt. I know at least one of the catalytic converters is impacted (rear based on the sensor reporting).