Rep Power: 0

I recently upgraded the exhaust on my son's 2000 civic, replacing the cheap header with a Megan Racing header and replacing the loud cheap glass pack with a 60 series Flowmaster "tucked" with a flat black down pipe. The header is good quality and the muffler sounds good but has a much quieter interior sound level. Now the problem. After a couple of days of driving the CEL came on and the code is the aft cat O2 Sensor. My son tells me that this is adversely affecting drivability and gas mileage and thinks that replacing the O2 sensor may not solve the problem. He thinks that with the improved air flow from the header, that a new O2 senor might still code, and that he should install an "O2 Simulator" . Any thoughts on this? E Check is not an issue in our county/state anymore, but I want to put in what is best for the car and keep the CEL off. New O2 sensor or O2 simulator? Thanks!

 
Rep Power: 276

defouler...aka 02 sim... you can get it at autozoo, oreilys, advanced.... theres a link in the DIYs for the defouler...
https://www.civicforums.com/forums/7...simulator.html

 
Rep Power: 304

i agree.

the defouler/o2 simulator is only $3. give that a try first, then move onto more expensive options.

your CEL light shouldnt be on with just the replacement of a header/exhaust, unless you took out the catalytic converter.

 
Rep Power: 256

it depends if you have room or not for which simulator on my car the cat was on my header so there was no room for the autozone defouler trick i had to buy a megan angled simulator it bends in a L shape to fit BLOX also makes one.