I've looked in this section looking for answers but cant find anything! My 5.5 is throwing 2 o2 sensor codes. I can tell my cats are clogged and I want to gut them. From what ive seen everyone talks about a sim or non fouler. Do I really need those? What are they? I don't have emissions or anything out here so im not worried about that. I just want my car to run normal and get my mpgs back! any help would be appreciated.

 

Secondary 02 sensor monitor the condition of the precat. If the car have error code for secondary 02 sensor, you need to replace the precat , gut it or install headers.The cheapest way is to gut it and install nonfouler to the secondary 02 sensor so it will not trigger SES light. If you live outside tristate, you can install headers with 02 simulator.

 

false.

 

^^ Yes, of course. Bad o2 sensor? Replace the ****ty cat! Great advice.

 

The primary 02 sensor or upstream 02 sensor is located before the catalytic converter to determined the level of emission and unburned gasoline.

The secondary 02 sensor or downstream 02 sensor is located after the catalytic converter to measures the emission after the converter If the emisson data between the primary and secondary 02 sensor is the same. The vehicle's. ECU will trigger an error code, which turns on the Check Engine light.

Iam referring to error code specific only for SECONDARY 02 SENSOR

 

^^

Anyway, to answer OP post = Yes you will need at least one sim or anti-fouler. Some people need both banks, some (like myself) get away with just one. That depends on the car too, IE. vq30 vs vq35

 

Like this man said, you will need sims or nonfoulers. It's cheaper/easier to just get the nonfoulers. You will need two (one for each secondary o2). It will keep the SES light from coming on and throwing a code

 

If I don't get Sims and it throws the code, will it decrease any power of my car? I tried to gut them last night but had a stripped bolt on my y pipe. Its the vq35 by the way. Thanks for the input so far guys!

 

The SES light will stay on. As long as the precat is gutted, it will not affect the engine performance. If you have a lot of corrosion , you need a torch or WD40 or you will ended up breaking those corroded nuts and bolts.

 

You don't have any performance issues. You will just have an SES light glaring at you day and night until you do something about it.

 

why would you need to replace the headers? i could understand if they were cracked.