O2 sensor cel question?

[TheShadow]

If the cat on the exhaust is removed and the o2 sensor throws a cel does it effect any kind of computer settings or does it just throw the light? I have a shop that is willing to build me a long tube header but it is gong to delete my cat.

[Mavrik]

well if the sensor is removed then it will throw a light as its not getting any reading from the sensor. Now if there is a sensor after the cat... without a cat then that sensor will get different readings and may come on as well. I don't know much about the location of our 02 sensors though to be offical on the matter.

[Digger]

if you search you will find a post on how to build a set back to put the sensor in to make it all work.

[4azdmunky]

I am not sure about the vibes, but my saturn would throw a CEL light and the PCM would switch into limp mode. I had a problem with my MAF sensor, and when the CEL light was on, my car ran like poo. Not sure if the PCM went into limp or if the dirty sensor was causing the car to drag (removed).You will more than likely want an O2 simulator to replace the one at the cat. I think they arund 70$, someone else may have more current pricing.

[joatmon]

A cel from a bad maf means the engine doesn't know how to properly control fuel/air mix, so it will go into limp mode to prevent damage. The second O2 sensor is pretty much there to just keep an eye on the performance of the catalytic converter, to let you know if you are potentially not meeting emissions standards. If the cat is bad, or not there, and the diagnostic system is working correctly, you'll get a CEL but the CEL won't affect the way the engine runs. THe O2 sensor in the exhaust manifold, th4e one before the cat, is used to help control fuelair mix, but the second one is just a catalytic converter diagnostic tool.THe problem with letting it throw a CEL (probably P0420) is that it would keep the CEL lit up, and you'd never notice if another CEL causing error condition arose.

[satur9]

have them weld a bung for it in the new collecter. and extend the o2 sensor wires

[Lancer]

Trust me, it's going to be loud without any cat!I blew the first one out. Second cat was clogged with the contents of the first cat. Had the first hollowed out and the second removed, then 2.5" piping all the way to the stock resonator and axle-back exhaust. I had to put a inline muffler infront of the resonator to sorta calm it down. It's still too loud on the high way so as soon as I can get my Unichip remapped again I'll be putting in a highflow cat to make it more drivable with the family on the highways.The S/C loves the easy breathing, though.But for your question, The O2 sensor after the cat is ONLY for moniroting the cat's performance. It has nothing to do with how the engine runs. And don't try doing this (see pic) to fix the CEL, it doesn't work. (Maybe if I had one cat working it would?)

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