Volcomroofus

2000 xj sport 4.0L

Does anyone have a good place to get an O2 Sensor Simulator?
Are the sensors internally heated?
Anyone have experience with these?


Any help is greatly appreciated.

dukie564

why would you install one of these, especially if it's pre-cat. They are there for a reason, your engine will not run correctly without a functioning pre-cat o2 sensor.

post cat sensor? i guess...but note if you live in the US, this is illegal.

Volcomroofus

it's post cat, and note I don't live in the US so it's not illegal.
Plus I'm not talking about removing my cat, all I asked was about the simulator

Acidburn2448

Still o2 sensors are helpful...

Volcomroofus

Yes, that's why I need it so it will simulate my truck having a functional o2 sensor and run right.. Plus get rid of that CEL

dukie564

post cat o2 sensor has nothing to do with your truck "running right".

What is the CEL code?

black_771

Basically all a simulator does is keep the CEL from coming on, but your car or truck will run the same as if you had no O2 sensors at all. With a simulator you are just spreading out the cost of a cat replacement because the money you save not replacing the cat you burn over time by getting worse gas mileage.

I'd recommend replacing the cat and sensors personally. Removing an operational cat does NOTHING for performance.

dukie564

x2

Volcomroofus

"­Th­e oxygen sensor is positioned in the exhaust pipe and can detect rich and lean mixtures. The mechanism in most sensors involves a chemical reaction that generates a voltage (see the patents below for details). The engine's computer looks at the voltage to determine if the mixture is rich or lean, and adjusts the amount of fuel entering the engine accordingly. When the oxygen sensor fails, the computer can no longer sense the air/fuel ratio, so it ends up guessing. Your car performs poorly and uses more fuel than it needs to."

Basically IIRC, the simulator makes the engine run at the optimum mixture as if the o2 sensor was operational. I have no idea what my engine is going to try to do with nothing inbetween the 2 sensors. I'm not really looking for a performance boost as much as just wanting the CEL off. I have had it cleared a couple times so I doubt that it was just a mileage reminder. I don't know the exact code off the top of my head.

I'm in a different situation then everyone else. It's not like I can just run up to a junk yard or go to the store to pick something up. I live in a 3rd world country... they charge about 80% duty which would mean a 100 dollar part would end up being 180 bucks (not including shipping, port fees, and any other bull**** fee they want to come up with for my white a$$)

I've been troubleshooting an overheating issue for alittle over 7 months now and this is the step I was at. I thought maybe the cat was clogged so I just cut it out to inspect it and it didn't seem TOO bad. But in the 3 weeks that I've driven it without any type of exhaust system it hasn't overheated once. I thought maybe it was the muffler than. So I just threw on a "new" muffler that I had on my old truck for a couple days before it got wrecked. Everything seems to be going good so far so it's staying as is.

I want the CEL off so I know if something else comes up down the road... I'm not trying to transport illegals into your country or try to commit any kind of felony's, just want some advice from someone who has had experience with these things. Not really looking for a lecture on how I'm doing something "illegal"

I hope I'm not coming off wrong to anyone. I just can't seem to get a straight answer or help on this matter from anyone, on any forum..

dukie564

what he is trying to say is yes, you can run it without a CAT, and this o2 sensor simulator would likely solve your CEL issues.

The bigger point that you do not seem to understand is that the CAT also creates exhaust backpressure, which is required for the engine to function correctly. Without the cat, your engine will burn more fuel to provide the same power. So it's up to you...spend more money now on a CAT and new o2 sensor that should last the lifetime of your vehicle, or spend a lot more money over time because of your crappy gas mileage. Your choice. I think it's even more important for you in Antigua because i'm sure you pay a hefty premium for gas over there.

This item is not a "fix" for your issue, it only masks the problem.

Volcomroofus

The gas mileage isn't really too big of an issue. I use my ATV as my daily driver and really only use the jeep for when it's raining, when people need to ride with me, or when I'm going surfing or towing the jetski... At the moment, my overheating issue is solved and that's a higher priority to me then running rich.

Are the sensors universal? I find some that are exclusive to certain makes and models, none for XJ's; but I find some that don't specify what type of vehicle at all. That's my delimma. I appreciate your guys' input though. I'm planning on redoing my whole exhaust system eventually, just not anytime soon. This is a semi-perm fix. Priorities..

black_771

Haha, believe it or not, I actually understand what you are trying to do and I'm not trying to be your momma or anything like that. You asked a question and hopefully we can just answer it for whats its worth.

To expand on the simulator, you are partially correct, but I think you have the wrong idea of what a simulator is capable of.

• The ECU makes changes to the mixture based on various voltages or resistance from the O2. The only way the ECU knows how much fuel to mix is from reading the exhaust, which changes the resistance in the sensor. Then the ECU does a lookup in its fuel mapping table with one axis being resistance and the other is RPM to decide the mixture. The simulator basically hard codes the resistance so instead of have a fuel lookup table based on RPM and resistance, you have limited yourself to just one column of the fuel table. The engine won't run at its optimal level because of this. You could actually cause other issues which in turn could set the CEL off for another reason.
• The CEL is pretty basic really. It goes on or off based on the O2 sensors resistance being inside or outside preset range such as if it has no voltage at all.The simulator sets a resistance that is inside this limit so it stays off.

black_771

The universal ones simply don't have the vehicle specific connector for your exact truck, but a generic one. You will have to cut your harness to fit the connector. The vehicle specific ones already have the right connector on them so you don't have to cut and splice.

If you want to make the CEL go off, put a piece of electrical tape over it. Its cheaper and pretty much a slightly less technical way of doing the same thing.

dukie564

i think he's just referring to putting this in place of the downstream o2 sensor (post cat). The upstream (pre cat) sensor is the one that determines A/F ratios. He should be ok as long as he leaves that one in place. A simulator is ONLY meant to replace a post cat o2 sensor.

black_771

Gotcha.