For those of you who are using a test pipe or one of those obx "high flow" cats which actually seems to be a resanator to me......have you experienced any cel's. I was reading the review on the obx cat and the guy stated he got a "catalytic converter threshold to low" code that went away after adding the silencer back on his muffler. Just curious if anyone else has gotten these codes with this setup with a header and high flow exhaust. Thanks in advance

i have a 2.5" testpipe and i have my cel on. don't buy that obx high flow cat. there is a dude on this site who makes testpipes. his name is xtremers i believe. anyways, nice product and he delivers fast. go with that

I run extremers's test pipe,i recommend getting his, it is easy install and looks good. I had a cel at the beginning, and i didn't pay no attention to it. I reset the ecu awhile back and got the cel again, but now i get no cel's and car is running great except for my other problems with my motor/

The reson that CEL gets set off is because we have a second O2 sensor downstream of the car. This does nothing with your A/f ratio, its simply there to make sure your cat. works properly. If your cat were ever to stop working efficiently or say go missing (illegal) then this O2 sensor picks up the excess "fuel" (for simplicity ) and sets off the CEL.

You can

A. Get a resistor to fool the O2 ( this is just a suggestion for the purpose of educating a fellow board member on how this system works.)

b. keep your cat on

Then again theres those people that have ran for 2 years without ever getting a cel for that ( not that im stating I dont run a cat).

i run a testpipe , i have no CEL