hi all, this is my first post here. I have a 99 GS eclipse (2.0 NA auto). I recently installed a high flow cat and a cat-back exhaust. right after the install the check engine light came on. I've reset the computer by unhooking the battery, but the light keeps coming back. just before the install, i had the car checked out and nothing was wrong, so i know the check engine light is due to the exhaust install. any ideas?

 

Somehow I see this being an 02 sensor

 

What code do you have?

 

95% sure its the o2 sensor.. That could really be the only thing if you didnt touch anything else..

 

for sure the 02sensor not reading. Make sure it's installed correctly, or if it's reading correctly. Erase the code, and it should go away

Gus