smugsmog

Hey all,

Just the other day I took my car for a ride, and I see a CEL. I purchased a basic obd2 reader and I got a P0430 Code: catalyst system efficiency is below the required threshold Bank 2. I took it to a local mechanic and they confirmed that it was the passenger side Cat causing issues. Would the Emissions Warranty be voided if you have a car back exhaust installed? I have a Borla catback installed at the moment.

-I did look around on the forums and says its most likely an exhaust leak, but my shop I usually go to recommended that I take it to Lexus

Kramer

iTrader: (15)

You need to reuse new OEM gaskets that butt the cat-back up to the OEM cats. Aftermarket gaskets do not seal well enough, causing that leak. Also, whether OEM or aftermarket gaskets.......they are different sizes. You could have them on the wrong sides when installed. it is not easily noticeable.....you have to look closely at both of them. Hope this helps!!

Fysisist

I had the same code except it was driver side. Took it to the dealer, they replaced the cat under warranty no questions asked. Invoice was well over $2K. I have the Joe Z exhaust, which deletes the first small cat that is on the OEM exhaust. They definitely noticed the exhaust because they commented on the sound, etc. About a year later, got the same CEL. This time the dealer told me my warranty was voided due to the aftermarket exhaust and Takeda intake I installed, and declined any work on it. The whole experience is in this thread:

https://www.clublexus.com/forums/rc-...t-exhaust.html

I ended up installing O2 bung extenders. Solved the problem, but yes as far as the dealer is concerned my warranty is voided with regard to this unless I restore the OEM exhaust.

smugsmog

I actually did get OEM gaskets for the install so Im a little bit worried

Oh ok, I will take a look.My mechanics said that a catback is ok, but if you change the intake, then that could void the warranty
I ended up installing O2 bung extenders. Solved the problem, but yes as far as the dealer is concerned my warranty is voided with regard to this unless I restore the OEM exhaust

jafsport

if you already got the OEM gaskets on my other guess would be the O2 sensors have gone bad.

smugsmog

I hope not! The cel appeared to have disappeared but Ill be driving my winter car till days a re warmer. Is it ok to drive with a cel?

On another note, my winter car has the same CEL . Unfortunately, that one actually needs a new cat on the passenger side

Fysisist

For what it's worth my Lexus dealer told me it would not damage the engine in any way. In fact I had the same code on and off for about a year. I doubt the O2 sensor has gone bad. According to the dealer the problem is mainly one of insufficient back pressure causing an inaccurate O2 sensor reading. The service manager explained further to me that the tolerances are very tight on Lexus engines, i.e. the range of sensor readings is tight before a code gets tripped / CEL. This is one reason that Lexus has the famed reliability that it does, they design to preclude problems by limiting revs, tight tolerances to catch potential problems early, etc. Do I believe all that? Not really although the rev limiting at cold temps makes sense.