Cat delete.......Anyone? [LOCKED: OP BANNED DUE TO DISRESPECTFUL/INSULTING BEHAVIOR]

[Dick]

So will that work for the emission readiness test for the catalyst? And can you tell the system to not report a code in a 2023?

That, I do not know, as we've never done a cat delete on a Gladiator, but on previous deletes, an HP Tuner can do most anything, you can shut down all emissions input. Once the ECM is unlocked, and if I can get test pipes, I will let you know. ?

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[Blade1668]

On some older Jeeps a hollow "Cat" didn't throw a light or code. I had a CAT bust apart the core from being hot then hitting cold water or rock impacts. FYI the shattered core ended up plugging the muffler so it had to be replaced.
Well luck with the project, not my thing, I'll be leaving mine OEM.

 

[Minty JL]

Cats today are super efficient compared to back in the day (late 70s-90s)

I know Bill will agree

I'm hoping there will be a tuning solution in the near future. Looks like Procharger is or has some solution that is NOT advertised; but I know a local'ish shop to me...... well here is a video they just postde

 

[Dick]

Cats today are super efficient compared to back in the day (late 70s-90s)

I know Bill will agree

I'm hoping there will be a tuning solution in the near future. Looks like Procharger is or has some solution that is NOT advertised; but I know a local'ish shop to me...... well here is a video they just postde

I don't know Bill, but tell your dog I said hi.

 

[Sweetums]

Fairly easy to avoid. Now, I know some states check for the ECU to have a factory tune on it. That would be a problem. But for most anyone else (at least, on say, a GM LS engine), you can just set the rear O2 sensors to not report a light. The emissions check (at least here in Louisiana) is only checking that the emissions system is reporting, and that their is no MIL - they aren't checking the actual values being reported.

So, on my SS Camaro I could just throw on long tube headers, 'turn off' the rear O2 sensors, and get a sticker and no-one would be the wiser. However - I have been shopping for 'green cats' to go with my long tubes once I get around to it as they will function like OEM, my rear O2's can stay active, and the car smells better when you are around it. A note on this - I have noticed many companies selling headers for newer vehicles will not offer them packaged with off road pipes. Only cats. If you want to go cat-less you have to buy the headers only and then source off road pipes separate.

Now, my '93 Chevy step side with an LS swap does not have cats and the rear O2 sensors are turned off, but they do not do emissions checks on anything 1995 and older in this state, so not breaking any regulations there.

Reiterating - on my newer car I prefer to keep systems intact. It's pretty easy to do. On my older project truck where the regulations are almost nothing - I don't worry about it.

As for the OP - the cat's on these trucks are buried. If someone can cut them out and steal them, they will have earned it, lol.

That's what someone did with our Wrangler, the system would never show Ready for a test and we couldn't pass until we replaced the aftermarket ECU with one that actually checks all the sensors.

So no, that will not work in any place that actually does an OBDII test. If it's just a check for a CEL, then you can skate by on that, but most states or counties with emissions know about that hack and will look for it.

 

[Maximus Gladius]

Man, I'm going to have to look those words up, lol.

I looked it up:
facetious - ranking high on a great idea.
glib - quasi candid in nature
You definitely have his support.

 

[ChrisNLA]

That's what someone did with our Wrangler, the system would never show Ready for a test and we couldn't pass until we replaced the aftermarket ECU with one that actually checks all the sensors.

So no, that will not work in any place that actually does an OBDII test. If it's just a check for a CEL, then you can skate by on that, but most states or counties with emissions know about that hack and will look for it.

Actually - you're correct. I didn't elaborate fully (my fault, I haven't look into it in a while - had to refresh my memory). They do in fact look for actual readiness here, not solely MIL.

So - some states actually check for a correct (factory approved) ECU flash. Most do not. Most are just check for emissions sensors / systems that are reporting as showing 'ready'. The inspection station system does not know what individual sensor parameters ready means, just that the ECU is happy with the information it is receiving and it is saying 'hey, I'm good to go'.

Using certain tuning software, emissions systems can in fact be set up to show ready and pass OBDII emission checks even if deleted (like the rear O2 sensors, the evaporative system, etc.) To your credit, folks do not like to talk about the ins and outs as it IS a legal grey area. Most will tell you all of the legal methods of using the software and let you read between the lines at your risk. A well know software even requires you to take a short online class concerning emissions systems annually before you are allowed to access those parameters.

That is a reason alone why some states check for a factory ECU tune, because they know you can, in fact, program them to show ready and fool a normal emissions check (with an aftermarket tune). The way around those who are fooling it? Ensure you have a factory approved flash on your vehicle. But unless they are checking for a factory tune specifically, a legit readiness check still wouldn't find a carefully tuned out O2 sensor.

I would bet a big reason gas vehicle tuning and shops haven't been raked over the coals as hard as diesels (yet) is they weren't pouring out giant / obvious clouds of black smoke everywhere. Fast gas cars, aside from being loud/obnoxious, aren't typically pumping out literal clouds of soot everywhere.

Out of curiosity - I have a handheld scanner that can show emissions readiness. I'd like to connect that to my LS engine (an OBDII system) in my '93 Chevy (not emissions controlled) and see if my tuner years ago set the missing items to show ready or not.

I do plan on picking up some tuning software and dongle as I'd like to turn off AFM/DOD (cylinder deactivation) in my SS Camaro and I have some tuning I would like to learn to do in my older LS powered truck.

 

[Elff]

I had a higher flowing cat on a previous car and it would cause an engine code to pop as if I did a full cat delete. In HP tuners you disable reporting on P0420, but that does not disable the readiness codes. The cat test will never set.
In my State, you are allowed to have 1 readiness code not set and still pass emissions. Also, if you drive less than 5000 miles/year, that vehicle becomes emission except.

If your state requires all readiness codes to pass emissions, I do not think you can resolve that with HP Tuners [unless something has changed in HPT that I am not aware of] and pass emissions

 

[ChrisNLA]

I had a higher flowing cat on a previous car and it would cause an engine code to pop as if I did a full cat delete. In HP tuners you disable reporting on P0420, but that does not disable the readiness codes. The cat test will never set.
In my State, you are allowed to have 1 readiness code not set and still pass emissions. Also, if you drive less than 5000 miles/year, that vehicle becomes emission except.

If your state requires all readiness codes to pass emissions, I do not think you can resolve that with HP Tuners [unless something has changed that I am not aware of] and pass emissions

Could be! I'm trying to find where I've seen it before.

Folks are saying that setting them to 'do not report error' will cause no light and show readiness. It's multiple DTC's you have to select to do it (basically, everything associated with the rear O2 sensors). I need to order an MPVI3 and try it out myself

Edit: Here we go. In this case, it was over TWENTY DTC's that had to be set to 'no error reported' in order to show green / emission readiness upon startup. That's why it's pretty easy to overlook when tuning if you're trying to do it.

https://www.355nation.net/threads/how-to-readiness-monitor-make-them-all-green.52277/

In any case, when emissions are applicable, I just try to be on the right side of the law anyway.

Not having an inspection sticker here is a minor offense anyway - so if you can't pass. Oh well. My buddy hasn't gotten a new one in 6 or 7 years

 

[Elff]

Same here

 

[BourbonRunner]

There are race shops out there that can modify an ECU for an off-road only vehicle though, generally speaking for track cars where a light in the dash could cause a safety inspection failure let alone accidentally cover up an actual fault that throws a necessary CEL.

There are also other ways past this, some have used spacers on the O2 sensor to pull it back from the stream eliminating the code and not throwing the CEL.

And yes, cat-deleted engines smell bad, especially at cold start.

I have heard rumors of some shops being able to write ECUs on cars still driven to pass emissions tests post cat-delete but that sounds illegal.

 

[Elff]

Actually you can tune that as well
it's in the cat warm up parameters.

 

[ShadowsPapa]

OP is being facetious and glib about the stated reasons.

Anyone who knows where they are on these knows a thief would spend a lot of time getting to the cats on these trucks, and scraped knuckles. They aren't easily taken.

I keep my cats in the house so they can't easily be stolen. Gotta keep cleaning the litter boxes, though.

 

[Tbanks]

Yes, I cut open the cat, cleared everything out, re-welded it. Tuned out the check engine light. Turned on the vehicle and put back on the stock cats. It sounded like a honda civic with a hole in the muffler. It made it sounds terrible.

 

[Dick]

Yes, I cut open the cat, cleared everything out, re-welded it. Tuned out the check engine light. Turned on the vehicle and put back on the stock cats. It sounded like a honda civic with a hole in the muffler. It made it sounds terrible.

You do realize you could have just tuned the sound with exhaust, right? Putting the cats back in because you don't like the exhaust note is like reaching in the toilet and putting the turd back in your ass because you're hungry again.

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