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dummy O2's ????

original balzer

original balzer

1/2 ton status
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roosevelt utah
Do they work? Where do I get them?
My 97 has 4 O2 sensers and 2 cat.converters Check engine light code says bad cats. Im in a non smog area so Ill ditch the cats but need dummy O2s to fool the comp?

Or am I totaly off base here?

My old 91 when I ditched the cat only had 1 O2 b4 the cat. That truck I just put the real O2 in one side and never had any problems.

Balzer
 
The Feds won a suit against Caspers and they are having to pay damages and fines for producing the sims. I doubt they (or anyone else) will make them much longer.
 
I would say you need the O2 sensors for the engine to run right. The computer uses them to make the correct air/fuel mixture. Maybe I missunderstood your question but I think it's a bad idea to remove them.
 
It's the rear ones. The front O2's I assume are the "primary", measuring the exhaust pre-cat, the computer then takes those numbers and based on what's going into the cat, compares that to what should be coming out the other end of the cat. So while probably not necessary, if I was seeing both sides saying failed cats, I'd be investigating more closely, as it would be unlikely for both to fail at the same time.
 
If the computer never gets any numbers from the rear ones I believe you get an erorcode saying "bad O2s". As said they are probably not neccesary but if you remove them you have to reprogramme the ECM not to get an error code.
Sounds like it´s something with the O2 sensors that´s wrong if you get codes saying bad cats on both sides. As dyeager535 just said, they´re not failing at the same time
 
Its the rear ones I need to get rid of or fool. The computer doesnt reconize either side singely as it was single exhaust from the facotry. SO the code is just saying one of the 2 cats is bad.

From what research I have done it seams a muffler that isnt straight though design would sorta emulate a cat. conv. Placed between the O2's It would change the readings from front and rear O2's but I dont know if it would be enough. Also limits my muffler choices. I personaly dont like the sound of ANY flowmaster. People have their arguments but to me I still hear that emty can sound. I love my magnaflows on the 77 GMC, DEEP rumble. But magnaflows are straight though design.

I could just ignor the check engine light but I feel I could miss other problems that may arize later. The O2 code would prevent me from seeing another problem, as it would already have the check engine light on. Even if nobody sells the O2 simulators theres several web sites telling how to build them. I think I could manage them as they seam simple enough.

Once I figure this stuff out I can update this thread with the info I come up with. That is IF asnyone else is interested.
If you know much about it post up any and all info is welcome.

Balzer
 
I really doubt a muffler could be used to fool the O2 sensors...the muffler just changes the sound, not what the exhaust gas is made up of. A cat actually changes the make up of the exhaust gas.
 
original balzer said:
Its the rear ones I need to get rid of or fool. The computer doesnt reconize either side singely as it was single exhaust from the facotry. SO the code is just saying one of the 2 cats is bad.

From what research I have done it seams a muffler that isnt straight though design would sorta emulate a cat. conv. Placed between the O2's It would change the readings from front and rear O2's but I dont know if it would be enough. Also limits my muffler choices. I personaly dont like the sound of ANY flowmaster. People have their arguments but to me I still hear that emty can sound. I love my magnaflows on the 77 GMC, DEEP rumble. But magnaflows are straight though design.

I could just ignor the check engine light but I feel I could miss other problems that may arize later. The O2 code would prevent me from seeing another problem, as it would already have the check engine light on. Even if nobody sells the O2 simulators theres several web sites telling how to build them. I think I could manage them as they seam simple enough.

Once I figure this stuff out I can update this thread with the info I come up with. That is IF asnyone else is interested.
If you know much about it post up any and all info is welcome.

Balzer
Click to expand...

Removing the rear O2 sensors won't have any effect on how the engine runs. They're there ONLY to measure catalyst efficiency, nothing else. You can pull them and deal with the code, you can install O2 sensor eliminators like I linked to earlier in the thread, or you can have them edited out, maybe with something like HP Tuners. Don't think LS1Edit would work on a '97 engine. I've been running no rear O2s/no cats in my '99 T/A for over 2 years now (edited out with LS1Edit), and that's how most f-body guys run them.

I doubt installing a muffler in place of the cat would fix the readings, as it doesn't function the same as a catalytic converter - what goes in comes out the exact same, so there'd be no difference in running a muffler or a piece of pipe in place of the cat - it'll net the same results.

Also, removing a cat is worth about 2-3hp, dyno-proven. To me, on something like a truck, it's not worth the hassle of trying to get around unless it's an OBD1 truck and you can ditch the cat without any other problems.
 
Yea I dont think a muffler will work either, I gutted me cats on my 02 tahoe and as soon as I fired it up the check engine light came on. They measure the gas makeup before/after the cat. I replaced the back 2 02 sensors with sims and everything was fine. The truck ran no different, the light went off, and as far as anyone else was concerned it had cats...sounded pretty good with the borla but it resonated horribly.
 
dyeager535 said:
It's the rear ones. The front O2's I assume are the "primary", measuring the exhaust pre-cat, the computer then takes those numbers and based on what's going into the cat, compares that to what should be coming out the other end of the cat. So while probably not necessary, if I was seeing both sides saying failed cats, I'd be investigating more closely, as it would be unlikely for both to fail at the same time.
Click to expand...

"both sides" won't see ****, other wise you are quite right. What is the code you are getting? Catalyst inefficiency or O2 sensor codes? Downstream sensors are just Catalyst monitor sensors. Nothing more. The computer uses them to monitor the cats function. As the engine changes from rich to lean(as EFI does often), it counts cycles(the up and down of the rich/lean situation). If it sees the rear sensors doing the same thing or too similar to what the front is doing, the inefficiency code trips and you have a bad cat.

One other option for cat removal is this, go to the local autoparts store. Hit the HELP section. Look for 18mm, Spark Plug fouling extensions. They are designed to remove the spark plug from a combustion chamber that is soaked in oil(tons of blow by). You drill the hole larger and you can install an O2 sensor in them ;). Removes it from the exhaust stream and it won't trip any codes if there isn't a cat. Much cheaper than simulators.

Oh and for both cats to go bad at the sametime, is a very rare/strange thing. If it happened(which is fully possible), there is more likely a cause. Say the engine running way too rich and throwing too much fuel down the exhaust, headgasket leak(antifreeze will destroy a cat when it hits that hot catalyst), or some other outside factor. Just something to keep in mind.

And I seriouslly doubt a restrictive muffler would do enough to reduce the cycling of the downstream sensors.
 
Felony warning

Even if you live in a place where there's no requirement for emissions inspections, you're still required to keep the factory original emissions control equipment in place and operational. It's a felony not to do so. Where I live, adultery is a class-three misdemeanor, that means a $50 fine at worst, but if I gut my catatonic converter, that's up to twenty years in Talladega. And, although it's federal law, every cop in the U.S. has the authority to enforce U.S. law, state, local, federal or whatnot (so what's all the fuss about local cops enforcing immigration laws, eh?). So, if you get stopped for a busted tail light, and the cop decides to take a close look at the vehicle, and your A.I.R. pump is gone, you could be looking at serious prison time. And, you know, it's really a matter of some wise-arse who doesn't like trucks with big wheels getting it into his head that you're a "bad guy". Better off keeping that stuff working. My uncle, who was the chief of police in a D.C. suburb, said, "don't have any chinks in your armor and they can't hassle you."

I'm a lawyer in Virginia, but probably not where you live, so check with a local attorney on the legal questions.
 
If you only want to disable the rear O2 sensors it can be done for about $5 and some time. Purchase a pair of the extensions for spark plug fouling that are made by motormite. They are the same thread as the O2. You have to drill out the small hole to about a 1/2 inch or what ever size you need to get the O2 to screw in. Then just install the O2 sensor into the fouler and then screw it into the bung in your exhaust. I did this temporatily on my 2000 because one of my cats was bad. It works. It moves the sensor far enough out of the stream that it will not set the code.

You will see no improvement in performance on a newer vehicle by removing the cats, it will be louder. I ordered a new y pipe from hottexhaust and it was less than getting 2 cats welded in.
 
user said:
Even if you live in a place where there's no requirement for emissions inspections, you're still required to keep the factory original emissions control equipment in place and operational. It's a felony not to do so. Where I live, adultery is a class-three misdemeanor, that means a $50 fine at worst, but if I gut my catatonic converter, that's up to twenty years in Talladega. And, although it's federal law, every cop in the U.S. has the authority to enforce U.S. law, state, local, federal or whatnot (so what's all the fuss about local cops enforcing immigration laws, eh?). So, if you get stopped for a busted tail light, and the cop decides to take a close look at the vehicle, and your A.I.R. pump is gone, you could be looking at serious prison time. And, you know, it's really a matter of some wise-arse who doesn't like trucks with big wheels getting it into his head that you're a "bad guy". Better off keeping that stuff working. My uncle, who was the chief of police in a D.C. suburb, said, "don't have any chinks in your armor and they can't hassle you."

I'm a lawyer in Virginia, but probably not where you live, so check with a local attorney on the legal questions.
Click to expand...

It depends on where you live. My car is nowhere near "street legal" due to the exhaust, but I've never once had a police officer give me a bad time - I've actually been complimented on the sound a few times. I did take it to a shop in Virginia and the owner's head nearly exploded when he saw it didn't have cats, but other than that, never any problems. My car even passes inspection in WV fine, and has no smog equipment - no cats, no EGR, no air, and the exhaust is dumped at the axle.

I was actually pulled over once (non-moving violation, didn't notice my inspection was dead) and while it's quite obvious that my exhaust isn't "legal" (no tailpipes), the trooper never once said anything about it.
 
Pretty sure utah has a rolling age limit but I could be wrong I know it was 1991 and newer for a while then I herd it was 1995 and newer. But like I said they dont enforce emissions here so Not many people know what the law actualy is. Utah is dictated by a buncha morons that never can leave the law the way it was the year b4. Take tint and lift laws for example. They have had the tint and lift las so messed up that nobody knows whats legal and whats not. last I knew the lift law was 24" 26" and 28" respectivly for 1/2t 3/4t and 1t trucks bottom of the main frame rail to the ground. But there are alot of trucks with over 10" lift and huge wheel tire combos. I havent even herd of anyone getting pulled over for lift in like 2 years now.

Anyway im not worried yet, and they cannot proove I personaly changed it anyway. When they start emissions here Ill change it but till then Im not gunna spend the extra money on a 10 year old truck. I do know the exhaust shops told me they do not have to put them on if they are missing when the truck gets there.

Balzer
 
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