ur car is obd2, u have a second o2 sensor on ur stock cat, using the test pipe eliminated it, hence ur cel.
Originally Posted by JDMmike
Hi im new to these forums I came here to get a question answered.
My check engine light on my 98 civic just came on and I cant figure out whats wrong. I recently installed a test pipe about a month ago, I dont know if this might of caused it, but why would the light come on now. Im not sure whats wrong plz help!