Vassago

So my car has been throwing the bad o2 sims code on the ignition light for a while now, I added a electronic cutout on my flowmaster exhaust right around the time i started getting the code so i didn't really pay any attention to it. Now my car is giving me problems.

It starts up fine but idles choppy and when i am at a stop light when it changes to green i release the brake the car will not go till i press the gas down at least halfway or sit there and wait for the car to go. It only does this at low rpms.

Do i need to replace the catalytic converters as well as the front o2 sims and get the rear o2 sims deleted. I know of the mail in order car tune from http://www.tunedbyfrost.com/products_m03.htm
but i cant be without my module for that long as my car is my DD. A local shop here will charge me 500$ to do cherry bomb cats or i can get any high flow cats i want and they will put them in. Any advice or help would be appreciated. Thanks!

The codes are:
p0420 & p0430 Catalyst Efficiency below threshold on both banks
p0171 system to lean on both banks

TransAmWS.6

The PO420/PO430 codes are signs that both of your cats are likely shot, it's usually not going to be the O2's in most cases.

Vassago

Ok thanks. so getting the new cats or high flow cats will i need new o2s in the front? or can i just get a tune or get o2 sims for the back?