Joshcivic00

I just got new brembo rotors and pads put on yester day and the mechanic ran the obd2 scanner and he said that i have an o2 sensor that is not working like it should,i am throwing throwing a CEL saying fuel system malfunction due to running to lean or too rich! the thing is i just put two new o2 sensors on when i got the greddy turbo put on and i have had the CEL since the turbo was put on. I was just wondering that since i have a high0flow cat and the tuner guy at the shop strapped the new o2 sensor outside the CAT and left the old one unhooked inside the cat,if it could be causing the CEL?? if not any other ideas of testing the o2 sensors to see if they are working??

thanks!

Jafro

Yes. That's the problem. It doesn't sense any fuel at all, so it's throwing a code. Pull the old o2 sensor out of the cat (throw it away), thread the new one in, and it should go away. It sounds to me like he only did half the installation.

Is the code a P0420?

Joshcivic00

im not sure what the code is,but thanks for the help!ill do that tommorow,you get to it by taking up the center console right?

Jafro

Nah. Usually it's behind the passenger side carpet. Do a search for "check engine light connector" and you'll probably find a complete how-to. P0420 will be an OBD-II code for cars made from '96+. Diagnostics are different on those vs. the '92-'95 cars. '92-95 cars are much easier to pull diagnostic codes from. I think the OBD-II cars require a scanner. Someone correct me if I'm wrong.

If you have to pay for someone to pull the code, then for now I'd just install the new o2 sensor in your cat, reset the ECU, and see if it comes back. That would be a free test. If the light comes back on, go get someone to check the code. The way your o2 sensor is hooked up right now WILL cause check engine lights.