as far as i know it doesnt affect anything it simply has to do with the emissions of the car. the only thing for me is that i have to go to a shop take off my exhaust and midpipe then go drop the car off at lexus for like 3 days then go put the exhaust back on...its a pain in the ***. i see some cats on ebay for $100 might as well just buy one and take it to my mechanic....
But there is this http://www.ebay.com/itm/MAGNAFLOW-99...ht_2032wt_1163
and then there is this http://www.ebay.com/itm/MAGNAFLOW-50...ht_2032wt_1163
i wouldnt need the 2nd one right?

 

What's the Bank 2 sensor 2 reading?

 

It looks like the second link is the cat and the header piping. You should only need the first one, but check with your mechanic just in case.

 

i dont remember exactly something about insufficient levels or something like that...i could go to advanced and get another scan if it would help?
btw the light is now back on....for a moment there i was happy i wouldn't have to deal with this lol

 

Too be honest it gonna cost you more money than it would be to just put the stock mid pipe back on an get brand new header from the dealer.Cause you mechanic is gonna have to drop the header, hack it up to fit the aftermarket cat.

 

Not sure if this will help anyone but I was aware of the carbon build up issue so when I started getting a P0420 trouble code to routinely come on after 77k miles on my '06 IS250 AWD (catalyst system efficiency below threshold bank 1), it was time to take it to Lexus and argue that the carbon build up is causing the rough idling and is also damaging the cat, causing the trouble code to pop.... They wouldn't confirm that the cat was under warranty to 80k miles like I've seen in other posts, but They did acknowledge the carbon build up issue and replaced the pistons and decarbonized the cylinder heads, etc. And also replaced the failed cat as a goodwill gesture. I was very satisfied with how the dealership handled this issue, especially because it did not cost me a dime! Apparently the engine is covered under a nine year Lexus warranty. Try to take advantage of the carbon build up TSB and argue that it's damaging the cat.

 

Did your car smoke and smell under heavy acceleration? What did you end up doing to fix this problem?

 

Rockauto (also on Ebay) will ship midpipe & converter for less than $200.00 ea.

 

^^^^That question was asked two years ago, and your answer really does not even address the question

Lou

 

P0420 This code popped up yesterday and I went to autozone to see what the problem was. Popped up twice they said it was my catalytic converter. What should I do? Also The check VSC, check Engine light and trac off light is on

 

I'd first check for an exhaust leak. My panel lit up with the same lights and trouble codes, and I ended up having a small hole/crack in the mid-pipe. I had a local shop spot weld a piece of metal over it to seal it, and I never had the issue again.

 

The ECM uses sensors mounted in front of and behind the Three-Way Catalytic Converter (TWC) to monitor its efficiency.

The first sensor, the Air Fuel Ratio (A/F) sensor, sends pre-catalyst information to the ECM. The second sensor, the Heated Oxygen (HO2) sensor, sends post-catalyst information to the ECM.

In order to detect any deterioration in the TWC, the ECM calculates the Oxygen Storage Capacity (OSC) of the TWC. This calculation is based on the voltage output of the HO2 sensor while performing active air- fuel ratio control, rather than the conventional detecting method, which uses the locus ratio.

The OSC value is an indication of the oxygen storage capacity of the TWC. When the vehicle is being driven with a warm engine, active air-fuel ratio control is performed for approximately 15 to 20 seconds. When it is performed, the ECM deliberately sets the air-fuel ratio to lean or rich levels. If a rich-lean cycle of the HO2 sensor is long, the OSC becomes greater. There is a direct correlation between the OSCs of the HO2 sensor and the TWC.

The ECM uses the OSC value to determine the state of the TWC. If any deterioration has occurred, it illuminates the MIL and sets a DTC.

Possible trouble areas:

• Gas leakage from exhaust system
• A/F sensor (bank 2 sensor 1)
• HO2 sensor (bank 2 sensor 2)
• Exhaust manifold (TWC)
• Front exhaust pipe assembly

You want a technician with, at least, Master Lexus/Toyota certification diagnosing this. MDT preferred. If non-Lexus or Toyota, at least L1. It's not hard, complicated to diagnose but it is easy to misdiagnose. Misdiagnosis is costly. It take me about 30 minutes to an hour to diagnose a P0420 or P0430.

 

My 04 ES330 170K engine was replaced with a used 95K engine by a Toyota dealer with 1yr/12k warranty. 1 month & 1k mi later I get a chk engine light (P0420 bank1 code). Dealer said needs a cat converter at my expense. My question is how can I determine if the issue is related to their replacing the engine (exhaust leak, sensor wire etc.) or if the cat simply needs replacing. I did not smell anything nor does performance seem sluggish however since the engine was replaced it appears to have a minor exhaust noise which they don't hear. We don't have a Lexus dealer nearby.

 

^^^^Welcome to the site. You would be better served by posting your question in the correct forum:

https://www.clublexus.com/forums/es-...1990-2006-179/

Lou

 

If I was your technician I would have asked you to sit down to chat about what lead to the demise of the engine you wanted to replace. Without this information we would be skipping a very important part of the repair process. Then, I'd perform a health check with a Techstream. After that, I'd check your catalytic converter by performing an active test with which I'd force your fuel trim to go rich/lean and check to see how the sensors are reading those conditions.

If there's an obvious exhaust leak, well, I'd investigate it. Think about it for a minute.... where does an exhaust leak need to be to impact the oxygen charge enough that the sensors pick up the reading? Here's a hint, a muffler leak won't cause a P0420/P0430.

If I had to suspect the engine swap process I'd look for a large exhaust leak near the catalytic converter, sensors, etc. I'm speculating but speaking from experience, this seems like a classic case of a condition that existed prior to the last service performed that has manifested itself after service (service, in this case, being the engine swap). Refer to my opening sentence. I have enough experience to warn my customers that if they do not tell me the whole truth they can be looking at a lot more money being needed for repairs. If the head gasket failed, if bank one was dumping gas into the exhaust due to a stuck injector, leaking head gasket, cracked water jacket, etc, those could all cause the catalytic converter to fail.

Good luck.