2020RCF

As the title says, ugh...nothing but issues since I started messing with this thing. The car runs amazingly so I just don't get it...are these newer vehicles that sensitive?! I had to get the windshield replaced due to it breaking on my way to Dallas...no idea how, didn't hear anything, just saw a huge crack. Then right before I put it in the shop, the check engine light came back on....again. Prior to this I got the check engine light when I put the intake on...got that fixed...then when I put the Invidia exhaust on, so I put the suggested thicker gasket on it and all was good until now. I've called Invidia and they said they've never heard of these issues before...even though all you have to do is google it lol. So, now the shop says it's the catalytic converter, which I got that code & O2 sensors when I installed the exhaust & we knew that couldn't be the case. So tired of messing with this thing. I bought it in Oct 2023 and really haven't even enjoyed it due to the constant CEL coming on. I just want no CEL and to enjoy the damn thing! Any suggestions are very welcome...thanks in advance!

brendanf

So just for my clarity, the latest code is for a catalytic converter and the only mod you have done is an Invidia exhaust?

Or is this a new CEL and you have yet to pull the codes?

This does seem very odd either way as they are extremely reliable. Is the shop that did the exhaust install and subsequent gasket replacement familiar with Lexus cars or just some shop that was cheap?

2020RCF

I have a Takeda intake and Invidia exhaust. The latest CEL said O2 sensor at first so the mechanic cleared the code...drove it, the CEL came back on so he plugged in and it gave him the code for catalytic converter. Now, when I first got the exhaust installed I kept getting CEL...sometimes it said O2 sensor, sometimes catalytic converter (we kept clearing the codes and adjusting then retesting)...so I had the suggested Grimmspeed extra thick gaskets installed and no more CEL. And no, not a cheap shop...the guy has been there for 20+ years and has worked on several of these so I'm assuming he's good...who knows though. So, I'm wondering if I jarred something loose on the exhaust on the drive to Dallas last week...like created a leak or something? Otherwise I'm looking at having to go back to completely stock...which I really do not want to do.

brendanf

You mention there was an O2 code at one point. Do you happen to recall what the code was? I ask because the ECU relies on the O2 to determine catalytic performance. If an O2 is reporting faulty info, the ECU doesn't know unless the data is really skewed which the ECU would realise is in-plausible and then cause an O2 code.

The O2s are also mounted in the Invidia pipe so it is plausible that one was damaged during the installation. It is worth inspecting the wiring carefully all the way to the connector.

Afterwards I would suggest your tech test to make sure the O2 is performing correctly. He may not have the tools/knowledge to do this as mechanics have a habit of just reading codes and assuming that is what needs changing.

Personally I highly doubt you have a cat issue and is likely an O2 wiring issue like a heater damaged.

brendanf

I just saw your comments in another thread about this same issue where you replaced the O2 sensor.

Did you use an OEM sensor or a cheap one like a Doorman?

LoSt180

It would be better if you got the specific codes than saying generically "O2 sensor" or "catalytic converter" because those really aren't accurate statements.

My recommendation at this point since you're having so many issues is to throw all the gasket fixes at it at once. First order four new nuts and bolts from Lexus (they are locking and may be coming loose with repeated removal). Keep the thick gaskets you already have, but pick up a tube of copper gasket rtv, and the thin walker donut gaskets. Put the thin gasket on the manifold side, liberal use of rtv on both sides of the Grimmspeed gaskets, then reassemble.

If paying a shop, tell them to assemble exactly as instructed because you will not pay them to redo it when the codes come back.

I'm on mobile right now, but I have a whole tech tip thread on how to deal with the Invidia gasket issue. If there's still an issue after following that, then either instructions weren't followed exactly or there's some other actual problem (most commonly twisted sensor wires).