So Im going to be putting the thundermuff exhaust on today and had a question. My last exhaust was a n1 ripoff with a test pipe cat. Even tho my o2 sensor is plugged into the cat, its throwing CEL. My question: should I get a regular hi flow cat...and who makes a good one? Whats the difference between a hi flow cat and a test pipe?

thanks! MUCH appreciated i wanted to learn about this before i tore the old exhaust off

 

I am using a universal fit Magnaflow hi flow... I like it.... I throw a CEL about 2 times a week but only for a couple minutes when the car is cold. I dont know why. The code isnt even applicable to my car so I am even more confused!

 

yea thats what im worried ill do too. I suppose just 02 simulate and be done with her ay?

 

Magnaflow or Randomstech make really good high flow cats, with either of them you shouldnt throw a CEL

on a side not, did you get your refund yet?