Hey guys, recently got a check engine light come on. I ran to the auto parts store and borrowed their OBD2 tool and came back with the P013A code, O2 sensor.

“Oxygen sensor slow response - Rich to Lean bank 1 sensor 2”

The car drives exactly the same still, and still getting 25mpg highway.

I reset the code to see if it’ll come back, but unsure if this was the right thing to do.

Some things to note: I had recently filled up gas at not my normal station.. also I have an invidia exhaust (but it’s been on for a long time without issue).

Any advice here? I read different things on different forums so was wondering if anyone here had the same experience or advice for me.

 

Check your exhaust gaskets and the O2 sensor bung.

 

It's a gasket leak before the O2 sensors. Try tightening the bolts and see if that resolves it. I had my Invidia on for about a year and 5K miles before I got a CEL. I ended up replacing the Invidia front gaskets with grimmspeed gaskets and that resolved it for me. I didn't even need to remove the O2 sensors. I propped up the exhaust, removed the four bolts, replaced the gaskets, and put the bolts back in.
https://www.grimmspeed.com/grimmspee...caAqABEALw_wcB

 

Thanks guys, I appreciate the advice. I should probably be able to do this just with a jack and a few jack stands right?

 

You can also use sealant to avoid a leak. Yes, you will have to jack the car up

 

I did it with ramps in the front and jack stands in the rear.

 

Just took a look, everything looks to be pretty snug and have installed over a year ago.

so maybe it really is The O2 sensor?

any of y’all know what sensor I would need? Do the generic ones work or do I need to get Lexus specific ones?

 

Also ordered those grimmspeed gaskets. Going to try to replace them anyways and see if it works. $50 and some elbow grease a little easy than spending on new sensors.

 

It's probably the gaskets and not the O2 sensor. It's worth upgrading the Invidia gaskets and seeing if that clears the CEL. When I replaced the gaskets, I could see the exhaust leak on one of the Invidia gaskets.

 

Much appreciated @Sunny.

Mind helping me again real quick? You'll have to forgive me as I've never done any exhaust work... So I jacked it up again to get another look.

I took some pictures and you see the sensor closest to the front right after the cat (green). there doesn't even seem to be any gaskets at all here... Does it need them? and is this the issue?
and then you look at the mid section (blue), and it seems like there might be a leak on the right side one where i've circled... But it's pretty far away from the sensor.. could this still be the issue?
And then the back end (red) don't think it's the issue, but let me know your thoughts.

 

Looks to me like they used an OEM gasket at the front and not the Invidia gaskets that came with the exhaust. That is almost surely where your leak is. Some people say to use OEM gaskets, but the OEM gasket is made to fit in a groove that doesn't exist on the Invidia exhaust.
I actually purchased new OEM gaskets for my Invidia, but when installing it, I went with the 3" flat gaskets because if you don't get the OEM gasket lined up perfectly, you will get a leak and CEL.
I would recommend the grimmspeed gaskets for anyone installing an Invidia or trying to fix a CEL.
The mid section and rear gaskets will not cause a CEL and those look like the Invidia gaskets that came with the exhaust. You don't want any exhaust leaks, but the only one that throws a code is by the cats and before the O2 sensors.

 

Awesome, thank you so so much.

ordered those grimmspeed ones you linked!

 

The picture above should be used to show people why the OEM gasket is not the one to use. You can clearly see a gap all the way around and just as noted if the gasket isn't PERFECTLY centered you are going to get a leak some where... IF, there was gasket sealer in between all that it probably would be fine for some time... but OEM gaskets shouldn't be used with the Invidia. When I put the OEM gasket on the Invidia pipe I noticed that one, it was too small, (since the invidia diameter is larger than the OEM exhaust piping), and two if it's not perfectly centered meaning you don't tighten the bolts and make sure the invidia pipe doesn't move at all, you are asking for a leak. It's not the correct gasket for the application.

I would have gladly paid a couple hundred more however for the Invidia if they would use OEM flanges that have the recessed area like OEM. I know the Borla had a recessed flange area. To me then you could use the OEM crush gasket and never have to worry about a potential CEL.

I will note that I also used grimmspeed gaskets but I used their double thickness 3" gasket which is 12 layers thick with a fire ring.

-Nigel

 

Yeah it's definitely been a learning experience so far. I'm planning on getting some sealant as well to coat it after I install the gaskets Sunny linked above.

I'll keep everyone updated! Would the process be, install and then clear the code and see if it comes back? or just wait to see if it goes away on it's own?

 

Sorry to muddy the water here, but normally with a leak you'll get a P0420 or P0430 catalyst below efficiency code. The slow response error could potentially be a problem with the sensor itself. Since most people don't pull back the carpet and unplug the sensors when installing an exhaust, it's fairly easy to get excessive twists in the wires for the sensors. Twisted wires could certainly interfere with the signal and trigger some codes.

The gasket advice in the thread is solid. You are correct in your assumption of the process: replace gasket, clear codes, wait and see. However, while you are replacing gaskets, inspect the sensor wiring. If they seem to be twisted up, plan on replacing the O2 sensors if the code does come back.