Check engine light was on my g35 ever since I brought the car but I was told by the owner that it didn’t have cats, so my only thought was to buy aftermarket cats. No big deal… until I replaced the cats and codes pop up for all four 02 sensors upstream and down streams.

 

Not entirely surprising that there were old sensors left in there also. I noticed, even my car without an error, replacing the sensors helped significantly over my old 100,000 miles of old O2 sensors.

However, you should check to make sure they are connected at the other end, hopefully no one just cut the wires on you.

 

Also, post exactly which codes it's throwing. If you have codes for all four sensors it's probably a blown fuse 85 in the IPDM since they all use that for a power source.

 

yeah I have Z1 motorsport high flows CATS and I replace all my 02s, I will try this out and I let you know if it works thank you

 

It was a blown fuse!!!

 

Gotta love a 2 $ fix

 

thank you it save me the trouble of blowing 2 grand at the auto mechanic shop.

 

Glad you got it all sorted out.