Still C.E.L.
 

Looking for help on this one guys, I need to get my damn C.E.L. light to turn off so I can get my car through inspection. I am running a complete aftermarket/custom exhaust setup so this may take some thought.



Current setup:

4-2-1 Headers with upstream 02 sensor in top of runner.

flex pipe

Catalytic converter

downstream O2 sensor

open pipe > inline muffler > over axle > fart can



I just took the car to an exhaust shop to have them cut out my old catalytic converter and install a new one further forward so the rear O2 sensor could be placed behind it. I was going to have the upstream sensor moved down to the collector, as per faith's diy, but the tech at the shop recommended against it stating that measurement needed to be taken as close to the head as possible. The old fitting for the downstream sensor (located in the collector) was plugged with a bolt, so it is still available for experimenting. After they were done they cleared my C.E.L. and sent me on my way. After only a few miles and 3 key cycles the light came back on, so I went back to the shop for a scan and turned up these codes.



P0135 Oxygen sensor Heater Bank 1 Sensor 1

P0141 Oxygen sensor Heater Circuit Bank 1 Sensor 2



The tech stated that he would assume from these codes that my O2 sensors are bad, but they are only 3-4 months old, so I don't think that is the case. Thoughts??

https://www.hyundaiaftermarket.org/f...-stupid-stuff/



you need it there cuz if you put it on the runner its only gonna read 1 cylinder



obviously you got a cel listening to him, so why not listen to me and try it

Ok, I'll give it a try.

so since its only getting a reading from 1 cylinder...then getting a reading after the cat from all 4



your car thinks either the cat is pretty shitty or the first o2 is not reading proper