BigBerz

The threads on the cat studs rusted off and so I'm left with the option of welding the pipe to my age old cat of unknown usefulness or just running a test pipe. Anyone here run a test pipe on stock ECU? I know it will throw a code but will it affect performance or MPG? What's better putting the o2 in a bung in the pipe or just strapping it to the outside of the pipe?

Berz out.

RS Design

it will throw a CEL but wont affect drive-ability , another way to bypass it is to buy a 02 sensor extender plug it all in and no CEL.. its the secondary 02 sensor behind the CAT that you need to put a extension on 02 Oxygen Sensor Extender Spacer Extension M 18 x1 5 HHO Bung 1 75" Longusa Made | eBay

not specifically that exact one. find one that fit a honda thats just for reference

BigBerz

Test pipe installed and here's my thoughts on it.

1. The V is now Quieter than it was with the cat installed. I am guessing I had a small leak from the rusted bolts for awhile that was allowing more noise than I thought. Now it's all being funneled out the tail pipe and the stock muffler is great. I was actually hoping for more sound than I got though.
2. I notice an increase in power for sure. I'm guessing the stock cat was far beyond it's useful time on a vehicle and was probably restrictive.
3. No CEL .... yet. I've got the O2 strapped to the sway bar for now.

Berz out.

RS Design

there are 2 02 sensors front of cat and rear of cat, by having the front 02 removed your car will eventually waste gas because the ecu is not getting the 2 value it needs to do fuel trim, and throw your car into limp mode with the CEL , one being the 02 sensor isnt being heated once the ECU runs through the monitors , but the 2nd 02 will throw a code and your car wont go into limp mode