Secondary cat delete
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Member
Joined: Jan 2016
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From: north Jersey
Secondary cat delete
Hey guys so I've been wanting to squeeze some more noise out of my truck and I noticed that the 2 rear cats aren't monitored by the 2 o2 sensors and I want to take them out. I live in NJ and want to know if I would fail inspection because of it but I don't think I would because they only do computer emissions testing. Any thoughts or ideas on how to easily do it is appreciated!
Monks
Joined: Jan 2016
Posts: 1,851
Likes: 249
From: Chuco Town, TX
Are you talking about the 2 downstream cats? They are monitored for catalyst efficiency, and have o2 sensors... If you remove them, you can do one of the following to shut off the check engine light (Needed to pass inspection):
1. get a custom tune to ignore those 2 sensors/ (I'd get a tune regardless, make the truck run better after the deletes)
2. Get a spark plug non-fouler (18mm) and use it in between the sensor and the pipe. This pulls the o2 sensor out of the exhaust stream enough to "trick" the PCM into thinking that the cats are operating efficiently.
3. Buy on of these (same as the non-fouler, just more $$), and install it in between the sensor and exhaust pipe.
Make sure that you do NOT reset the battery before your inspection. All of your sensors and mode 6 data needs to be back up in "Ready" state. If you reset the battery, this will take a while to bring all the sensors back to a Ready state.
Check your local laws to be absolutely sure that they don't do visual DOT inspections for emissions. If they do, leave the cats in.
1. get a custom tune to ignore those 2 sensors/ (I'd get a tune regardless, make the truck run better after the deletes)
2. Get a spark plug non-fouler (18mm) and use it in between the sensor and the pipe. This pulls the o2 sensor out of the exhaust stream enough to "trick" the PCM into thinking that the cats are operating efficiently.
3. Buy on of these (same as the non-fouler, just more $$), and install it in between the sensor and exhaust pipe.
Make sure that you do NOT reset the battery before your inspection. All of your sensors and mode 6 data needs to be back up in "Ready" state. If you reset the battery, this will take a while to bring all the sensors back to a Ready state.
Check your local laws to be absolutely sure that they don't do visual DOT inspections for emissions. If they do, leave the cats in.
On the trucks with 2 pairs of cats, the rear most set of cats with NO O2 sensors behind them can be removed. These extra cats shipped on 04-05 MY IIRC. If you remove your cats with the o2 behind them, you will get a CEL and not pass visual inspection or emissions.
Member
Joined: Jul 2015
Posts: 30
Likes: 2
No issues
I have a 04 Scab XLT with a 5.4,171K. After buying it three years ago with 156K I thought it had an issue with the cats?
I took it to my local exhaust shop and had it checked. They believed that the rear cats were clogged and recommended deleting them.
Had them deleted and haven’t had any issues. Also made the truck sound louder, but not unreasonable. No issues passing emissions in MA either.
I took it to my local exhaust shop and had it checked. They believed that the rear cats were clogged and recommended deleting them.
Had them deleted and haven’t had any issues. Also made the truck sound louder, but not unreasonable. No issues passing emissions in MA either.
Thread Starter
Member
Joined: Jan 2016
Posts: 70
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From: north Jersey
Originally Posted by Darrenh66
I have a 04 Scab XLT with a 5.4,171K. After buying it three years ago with 156K I thought it had an issue with the cats?
I took it to my local exhaust shop and had it checked. They believed that the rear cats were clogged and recommended deleting them.
Had them deleted and haven’t had any issues. Also made the truck sound louder, but not unreasonable. No issues passing emissions in MA either.
I took it to my local exhaust shop and had it checked. They believed that the rear cats were clogged and recommended deleting them.
Had them deleted and haven’t had any issues. Also made the truck sound louder, but not unreasonable. No issues passing emissions in MA either.
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Joined: Jul 2015
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Visual
They have cameras watching the inspection bays and you never know if they’re watching? Also they take a still picture of the front, back, sides, vin and the instrument cluster, but not underneath the vehicles. I have never had an inspection where they’ve look underneath at the cats.