O2 Sensor Simulator
 

Okay,

For some time I have been researching and working on a O2 sensor fooler for my "off road" blazer, since removing the cat converter. Removing the cat was much more difficult than I anticipated, but that's a different story.
I wasn't going to do anything after removing the CC, but my gas mileage went down the toilet and that annoying "check engine" light stayed on.

After a lot of reading, I decided on a $40 simulator with the heater I found on ebay. It was fairly simple to install - I cut the wires next to the O2 sensor and re-routed them up next to the ECM. I wired it according to the instructions, but used the ground wire that went to the original O2 sensor, which turned out to have a very high resistance. It caused the new simulator to put out a negative voltage.

I ran a direct ground off the chassis to the simulator and it started working correctly.

I wanted to pass on this info, since I have done a lot of reading on this site about the O2 simulators, but found only a few who made it work. I am anxious to see if there will be any trouble down the road.

It is an 'offroad' truck right?... What are you worried about mileage for?

Removing the catalytic converter should not have had any impact on your mileage. And you cannot simulate the upstream sensor(s). The only reason to use a simulator would be to fool the PCM into thinking it had a functioning cat which only deals with the down stream sensor(s).

Want more specific information, provide your vehicle details...

Off Road
 

Well, "off road" is tongue-in-cheek, cause technically removing the cat is illegal. I have a 97 4x4 with the 4.3. It has 170K miles and the cat was rattling something fierce. I got sick of it and decided to remove it.

Your truck has 4 O2 sensors. The two closest to the exhaust manifolds, one on each side, are required for proper engine operation. These two O2 sensors are responsible for proper AFR in the engine.

Besides, you might as well throw a $50 universal cat on it to stay legal. Fines are not cheap!

i would like to get me some o2 foolers too for the downstreem o2 sensors, one less sensor to replace later in my opinion, we dont have emissions and i dont care about fed emissions either.

better read the rules here, illegal is illegal

Now I know rules are rules but as this is concerned were does legal and illegal fall?

2012 (I believe) NYS dropped emissions for 95 and older, safety only.
As the date approached fewer and fewer stations had there dynos and sniffers fixed, they very soon would be out of date anyway.

It quickly became near impossible for about six months for anyone to get an up-to-date sticker with a 95 or less vehicle.

Hard to explain to a Judge, trust me, valid sticker or expiered:icon_sultan:those are the options !!!
95 with a 1.5 light on, auto-fail. "The Grand Pu-Ba" took pity and gave me two weeks to get proof of inspection or have $200 in hand (that's right, 200).

Well since my 95 had an obdii plug and could be read by the inspecting device, found a station that would put it through if the light was off. Post cat heater circuit. Certainly not a menace to society or the environment.

Did I do some thing illegal with my cheater, up to the man upstairs!!!

It falls under illegal as its a federal law against removing emissions equipment. Your state law can say whatever but fed law is over that. I live in arkansas and we have never had testing but its still illegal to remove or tamper with it. Also illegal to remove or tamper with airbags if it came from the factory.


Soooo just because the local laws aint pushing it don't think its automatically ok. All it takes is the wrong pig on the wrong day that knows what they looking at to fine ya and send your truck to the crusher.

God i would really hope they have better things to do then checking peoples post cat o2's or we're all doomed!!!

REPENT NOW! THE END IS NEAR!

Back to the point here about "foolers". The only thing that gets fooled is the buyer! When the PCM randomly checks converter efficiency, it commands the injectors full rich, then immediately full lean, and back to normal, (It happens so quickly you don't even notice it). The PCM "watches" how long it takes for the mixture change to reach the downstream O2 sensor. If the sensor reacts too quickly, the converter is "dead" or hollowed out and the SES light comes on. If it takes too long, the converter is restricted and the SES light comes on. It would take some pretty fancy electronics to know exactly when and how much voltage to produce to fool the PCM ;) Save your money.