Hi Honda-Tech, I finally sorted out my readiness monitors and smogged my car. Plugging in a non-fouler behind the secondary 02 sensor set enough monitors to pass. After having the part off the car for a week, my CEL (po420) came on. I have three choices, I can keep clearing the code as I go, I can re-install the non-fouler, or buy a new CAT.

The car passed the sniffer test just fine so I don't really want to replace (1996 civic DX - CAT built into headers $$$). I'm also saving towards a B series swap anyways so I don't want to spend money on stuff that's getting replaced.

My question is this - will driving with my non-fouler affect my running conditions? Fuel mix? Anything? I don't want to cause negative effects on my motor buy giving the ECU reading that are different than the actual conditions. Or just keep clearing the CEL?

 

You might want to google Citric Acid Bath for Catalytic Converters.

Citric Acid powder is cheap, you just need to find a container big enough to fully submerge your cat and keep the temp up to about 90F or so for 6-8 hours.

Studies show it returns cats back to 80-90% new status.

 

No harm in running with a defouler.