Catless Check Engine Light

[04BlackSRT10]

When I bought my car it had a ridiculous frankenstein of an exhaust on it that droned like crazy and had multiple exhaust leaks. I have since removed the crappy jiffylube special cats and exhaust and put on a Corsa with a piece of pipe where the cat used to be. The car didn't seem to notice or care for a few hundred miles, then randomly threw a check engine light. I checked the code and it was an 02 sensor failure code. Why did the car wait so long to throw a code? If that happens again will the car go into limp mode and/or run super rich, or will it just be an engine light reminding me to fix the cats? I can deal with a CEL being on for a little while, but obviously will have to get new cats asap if this is going to impact my performance.

 

[MoparMap]

I think it might depend on which code it threw exactly. I don't think the rear O2 sensor code is as big of a deal as it's typically a measure of catalyst efficiency and doesn't necessarily affect the tune as much. The front O2 is more the one that drives direct feedback to the fuel system to adjust things and if it was off it would probably run the car extra rich or open loop all the time if I had to guess. Fairly typical to have the rear O2 sensors cause issues with aftermarket exhaust from what I understand, I don't think I've ever really heard of the front ones causing issues.

 

[TexasViper35]

If the sensor is bad it should throw the code at cold start up; once the car is warmed up if it throws the code I would look at other items. You can clear the code with a scan tool and then see if it comes back. In my case I had that code but the sensor was fine, the problem was wires associated with the skip shift solenoid were chewed by rodents. The skip shift solenoid and the O2 sensors share a fuse. You might check that fuse and the wires to your sensor and skip shift.

As a side, my CEL would come on at random when the car was warmed up. It would reset itself after 3 short drives and stay off for days or weeks or longer. But eventually it just stayed on and I found the problem.

 

[hlieber50]

I get frustrated with Viper owners running catless. It's illegal and an environment issue. If you don’t care, tell that to your grandkids.

 

[Michael Murray]

If you don’t care, tell that to your grandkids.

I will not be having grandkids. My grandpa never told me he didn't care (although I know he couldn't have cared less ❤)

To the OP, 'O2 sensor failure' is far too vague, post an actual code, please.

 

[04BlackSRT10]

To the OP, 'O2 sensor failure' is far too vague, post an actual code, please.

The code it threw was P0430

 

[Michael Murray]

The code it threw was P0430

That's normal then! Sometimes it will take a while to set a code as the ecm has to see a specific driving cycle for it to know if the catalyst is indeed efficient or not.
It will in no way whatsoever affect performance to have that code.

 

[04BlackSRT10]

So, I decided to have cats installed, and did so today. The fuel smell was starting to bother me and the car was a little too loud and raspy. the cats solved all these problems and it's much more enjoyable to drive now. While I was in the shop I took a look under the car and there are actually O2 sims installed on the rear sensors. Odd that it threw the code the other day. I guess one of the sensors temporarily malfunctioned. Haven't had the codes return since that one time, so hopefully it won't happen again.