The Nissan Path

Hi all,
The two cats connected to the mainfold are clogged. Am looking at dumping them and replacing them with pipes. As for the o2 sensor i will try the spark plug non-fouler trick, if it doesnt work i dont mind the ses light being on. The question is would this affect performance or mpg and how ?
Thank you.

Disconnect o2 sensors and drive it

If you are gutting the pre-cats (which, of course, is illegal per Federal emissions laws), you will likely cause the ECM to trigger P0420/P0430 trouble codes and set the SES light. You "may" or "may not" experience a boost in performance. The problem is that being that the SES light will always be "on" for the catalyst codes, you will not know when other problems occur that would normally trigger trouble codes and could be detrimental to the engine, engine performance and/or gas mileage, such as cam or crank sensor codes, mass air sensor codes, etc.
The other question to ask is what caused the pre-cats to get clogged in the first place? They usually fail due to inefficiency in breaking down the exhaust emissions, not because of restriction. Restriction usually occurs when the catalyst substrate is contaminated by oil, fuel or coolant, which could indicate problems such as worn rings, excessively rich mixture and/or failed head gasket.

I have no idea how it ended up like this, i bouht like this from the dealer who didnt mention anything. Regarding federal laws, its no problem at all since i live outside the us.

Thupertrooper wrote:Disconnect o2 sensors and drive it

Won't that make it run inefficiently ?