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Discussion Starter · #1 ·
Hello guys,
Posting a new post specific to O2 sensor simulators. to those of you who have experience with catles dp, Which is better, Screw in type for rear sensor only, orrr digital version that fixes both upstream and down stream to work in harmony together. I am told that the upstream also needs adjustment for the increased air volume. HERE IS WHAT I AM TOLD from Magnum tuning.com " The life span of a sensor is 50k and We encourage customers to get the dual function simulator because aftermarket down pipes will ruin the signal of the upstream and down stream sensors at the same time. The simulator can replace what the sensors do. We recommend the unit that will act on both of them". what do you guys think. It kinda makes sense to treat the upstream sensor as well.
 

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Not sure what the simulator would do, as the downstream sensor really just measures the effectiveness of the cat converter, and on a carless DP, that's pretty useless, so most tuners just turn them off. The upstream actually adjusts AFR based on what's coming into the exhaust, and does need to account for increased volume. What does the simulator do better than the actual O2 sensor?
 

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I would rather not send false (Or what they call "fixed") data at all to the ECU. The rear 02 sensor really doesn't do much but you are messing with some finely controlled data by falsifying the wideband sensor. It sounds like it's the same as those plug in "invisible" tuners that just hijack sensors and send false data to the ECU. With as much control we have over the ECU and how much data it receives it just doesn't make sense to try and bypass it all.
 

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Discussion Starter · #4 ·
I think the point of the simulator is to simulate exactly what they would do without having to have them or have them mess up the ecu. The bypass system basically upgrades the O2 sensors to deal with the DP accordingly.
 

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"Deal with the DP accordingly" and "simulating what they do" makes it seem like it's sending false data to me. The stock 02 wideband sensor is pretty damn accurate and your ECU, especially with the Mountune tune you have, is expecting that data. The ECU can compensate for the downpipe on it's own. You don't need to trick it with simulations.

If you are just worried about emissions testing and the check engine light just get the defouler. Don't make this more complex than it has to be, especially when that complexity has a decent chance of causing an expensive bill.
 

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Discussion Starter · #6 ·
i have to say i like that answer! Your saying the ecu will compensate for free flowing exhaust and adjust my air fuel ratio with that precat O2? i hope so and yea your right! It makes sense actually. I do know for a fact that the rear sensor needs addressing with the simulator. i was just told that a bolt on defouler or something to pull the O2 away from the stream wont fix the issue. Fortunately i believe that Magnum tuning has the wiring harness module that allows the O2 sensor to stay where it is but just keeps it at its sweet spot as if the cat were still there. Basically it overrides it so that the ecu dosnt say " where is my cat!" lol
 

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i have to say i like that answer! Your saying the ecu will compensate for free flowing exhaust and adjust my air fuel ratio with that precat O2? i hope so and yea your right! It makes sense actually. I do know for a fact that the rear sensor needs addressing with the simulator. i was just told that a bolt on defouler or something to pull the O2 away from the stream wont fix the issue. Fortunately i believe that Magnum tuning has the wiring harness module that allows the O2 sensor to stay where it is but just keeps it at its sweet spot as if the cat were still there. Basically it overrides it so that the ecu dosnt say " where is my cat!" lol
Wouldnt get a simulator. ECU in the ST is pretty dam smart. You dont want any sensor giving false info.

You can have your tuner take out the Cat code (P0420) so the check engine light wont come on with an aftermarket downpipe

And yes, the precat o2 is very important. That is what tells the ECU your AFR and adjusts accordingly from that.


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