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Gutting precats

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Old 08-28-2014, 07:26 PM
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Gutting precats

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.
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Old 08-29-2014, 01:10 AM
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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.
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Old 08-29-2014, 02:05 AM
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Originally Posted by colt149
Secondary 02 sensor monitor the condition of the precat
false.
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Old 08-29-2014, 08:07 AM
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^^ Yes, of course. Bad o2 sensor? Replace the ****ty cat! Great advice.

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Old 08-29-2014, 09:06 AM
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Originally Posted by D.Stillwell
^^ 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

Last edited by colt149; 08-29-2014 at 09:09 AM.
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Old 08-29-2014, 09:12 AM
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^^

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
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Old 08-29-2014, 10:14 AM
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Originally Posted by D.Stillwell
^^

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
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Old 08-29-2014, 11:03 AM
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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!
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Old 08-29-2014, 01:03 PM
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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.
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Old 08-29-2014, 01:56 PM
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Originally Posted by Tyler Kadlec
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!
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.
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Old 08-29-2014, 09:49 PM
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why would you need to replace the headers? i could understand if they were cracked.
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