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Discussion Starter #1
Hi all

Im having a huge headache right now trying to fix my p0430 code (Catalyst system efficiency below Threshold bank 2)

Problems with my 02 5spd

Ive swaped my headers with my 01 that recently passed smog with flying colors onto my 02 which is having the p0430 code always pending and eventually being stored. This makes no sense how the code keeps poping up. Everytime it pops up i would just erase the code and all the monitors reset.
I keep forgetting the pull the neg term for the battery to reset the ecu. should i try doing that instead of just erasing the code?

also should i swap the ypipe as well, as far as i know the cat on the ypipe isnt monitor so it shouldnt trigger the p0430 right?

On top of the emission problem my car just started squealing, when i start to drive i hear a squealing sound, it sounds like my brake pads are bad but i check and they are in pretty good shape. So i came home turned off my car and got out the car when i noticed the squealing. it happens when i push it a bit.

Heres the video. Im writing this at 12:31 am so i have not inspected the car cuz im really tired and frustrated. Tomorrow im planning to check the brakes. Just looking for some suggestions and guidelines

Thank you for reading.
Is300 brake squealing - YouTube
 

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I might try swapping 02 sensors too. I have a theory that the newer the sensor, the more sensitive the efficiency CEL is because new 02's react faster than old 02's. From what I've read, with a good cat the rear 02 will switch slower than the fronts. The closer the switching speed between the front and backs, the less efficient the CAT is. When they get close enough it sets pending and then stored.
 

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To add, once P0430 pops up a battery reset probably won't do much as it's very likely it will come back. Erasing the code via scanner is a better idea because when you pull the negative, wait 5 minutes and then reset the ECU, all the monitors reset too, which take time to reboot. What I would do is some basic tests on the cats to see what's really going on. You can do this with a scanner, multimeter and cheap $20 IR temperature gun. Or have a shop diagnose it so you know if it really is the bank 2 cat, which is likely the case if you have no oxygen sensor codes(performance/range DTC's) and have no exhaust leaks. Running rich is harsh on cats but I would also expect you to have rich codes. I have heard bad gas with a high sulfer content can cause these codes but that's pretty rare and usually goes away.

There's a number of methods but the easiest is using a scan tool(borrow for free) and an IR temperature gun($25). You would watch your oxygen sensor voltages once the car has warmed up. The air/fuel or upstream oxygen sensors should always be switching very fast between 0.1 and 0.9 volts. The downstream oxygen sensors should always stay close to the middle or between 0.3-0.7 volts and not change very rapidly. If it bounces around from 0.1v to 0.9v then there's a problem. You can use a cheap infared temperature gun and check before the cat and directly after. The temperature before the cat shod ALWAYS be lower than the output temperature, usually by a few hundred degrees sometimes just 100*F. Output must always be hotter, otherwise the cat is clogged up or the honeycomb has failed and now your car will misfire and sound like a motor boat. Clogged cats can also get cherry red after a decent drive. Then there's also vacuum testing and checking for NOx, HC, and CO2.

Eric the car guy, a great mechanic, just did a great video on this as well.
https://www.youtube.com/watch?v=9VZ5K8n5jj0&feature=youtube_gdata_player

As for the squealing, it could be a number of things. I would get a helper to do what you were doing in the video and put a screwdriver or your ear near the front suspension. I wouldn't think it's brake related because the pads are relaxed but it may be harmonic noise. It could also be a wheel bearing or a front end bushing. Take the caliper off and try pushing it to rule them out, that should be a quick test.

Good luck.
 

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Discussion Starter #4 (Edited)
Update: I fixed the squealing noise by change my brake pads and greasing all the metal tabs and bracket. My old pair had really good meat left so im guessing all my car needed was a good greasing.

As far as the P0430 it has not yet poped out after i changed my b2s2 02. but i have only drove the car for 20 miles. I will do the obd testing when my friend is free cuz he has a obd with live data.

update 2: p0430 only pends when i rev over 5k
 

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Honestly, I was getting this code for a while. It is the catalytic converter on back 2... I changed the spark plugs and never had a problem since... My mechanic said to use Lucas Fuel Injector/upper cylinder cleaner lubricant and I haven't had a issue since. It has been months now.
 

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Discussion Starter #6
Ok so i went to my mechanic and used his IR gun to check the temps on the cats. yup its confirmed that the cats are done. inlet temp is 320 out is 246. ughh its weird cuz my 01 passed with the same cats.
 

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Ok so i went to my mechanic and used his IR gun to check the temps on the cats. yup its confirmed that the cats are done. inlet temp is 320 out is 246. ughh its weird cuz my 01 passed with the same cats.
Yep, it should be the other way around. Sorry to hear...
Maybe just grab a lower mileage used one for cheap or step it up to an aftermarket.
Good luck.
 

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Discussion Starter #8
Yep, it should be the other way around. Sorry to hear...
Maybe just grab a lower mileage used one for cheap or step it up to an aftermarket.
Good luck.
i was thinking about just going to one of those smog till you pass places. cuz right now i installed a 02 sim and the cel and pending codes are gone. just waiting for the monitors to reset now.
 

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i was thinking about just going to one of those smog till you pass places. cuz right now i installed a 02 sim and the cel and pending codes are gone. just waiting for the monitors to reset now.
Well you can try at least, don't know how well it will work IF they read HC/Co/NOx levels right off the tailpipe. With the cat's honeycomb broken down and causing a back pressure issue the car will act rich if the cats cannot perform their job, burning raw fuel. With an O2 sim you will have no warning sign if things get worse until the point one day where you open the hood and the cats look like ripe tomatos and runs runs/sounds like a motorboat chugging along. Lol
Seriously, with a much higher back feed and inlet temps much higher than the outlet, I would either remove or replace them before you have motor issues. Remember the SIM will not give you any warning because it will trick the ecu into thinking the cats are running great. Try Justlexusis300parts from eBay for a low mileage header if you are strapped for cash.
 

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Discussion Starter #10
Well you can try at least, don't know how well it will work IF they read HC/Co/NOx levels right off the tailpipe. With the cat's honeycomb broken down and causing a back pressure issue the car will act rich if the cats cannot perform their job, burning raw fuel. With an O2 sim you will have no warning sign if things get worse until the point one day where you open the hood and the cats look like ripe tomatos and runs runs/sounds like a motorboat chugging along. Lol
Seriously, with a much higher back feed and inlet temps much higher than the outlet, I would either remove or replace them before you have motor issues. Remember the SIM will not give you any warning because it will trick the ecu into thinking the cats are running great. Try Justlexusis300parts from eBay for a low mileage header if you are strapped for cash.
i just need to pass smog, after that i got aftermarket headers, and y pipe
 

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Well i installed the 02 simulator but since we cut the signal wire. its normal for oxygen sensor monitor to not complete right?
The 02 simulator should replace the signal wire information from the secondary 02 with bogus signal information. The signal wire should never be disconnected, not if you want to pass emissions. Either the 02 or the simulator needs to be connected to it.
 

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Not a good idea to sim any cat you know that is definitely bad, that's just asking for more trouble. Sure it may take the CEL of the dash for an inspection/emissions but if they read your tailpipe I would imagine there would be an abnormally high amount of emissions if the cats are not performing their job. I would be more worried about your bad cat(s). That's no place for a sim, they are meant to be put on cars without catalytic convertors.
 

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I'm with you there Jason but, sometime it's just borderline. My left cat is weak and I get a CEL that comes and goes. Lexus wants a grand for a new cat. I'm just waiting for someone to part a car locally so, I find a pair.

A melted car for sure is bad news but, even though my cat is weak, you can see right through the substrate so, there's no restriction to speak off. The fuel trims are normal too.

So, I agree with you in principal but, don't think a convertor efficiency cel always means dead cat. They just get weak as deposits build up over the catalyst part.
 

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Lucky where I live there removing emissions testing by the end of the year. I was able to pass with just the oem downpipe for visual purposes. And the computer scan came clean with Megan headers n o2 deletes from tokensolutions. Car was too low for the roller test and ended up having to back out of the place as well.


Sent from AutoGuide.com App
 

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I understand the cat efficiency codes can be triggered very easily with a slightly degraded cat, but in the Op's case there is restriction and as a result his engine performance will suffer as well as gas mileage.
az989 said:
Ok so i went to my mechanic and used his IR gun to check the temps on the cats. yup its confirmed that the cats are done. inlet temp is 320 out is 246.
That's aside from any damage that may be caused due to the high back pressure, which may not be too high right now. Inlet temps will only increase as the cats clogs up. Idk, just saying it's something I wouldn't put off as far as replacement. I would keep an eye on those temps as well.
 

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Discussion Starter #19
i just passed emission. its weird i used this thing called guarantee pass. the car passed with flying colors. well i got 2 years to look for a good exhaust manifold, catless manifolds are going into my car
 

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Glad to hear you passed, maybe your cats aren't too bad, not sure. The temperature difference still is a concern but you may be ok for a bit. The honeycomb can break down even more and cause much more back pressure, you will notice it if/when it happens.

But in my opinion, regardless if you passed, I would be looking into replacement cats or a different header. Keep an eye on the temperatures, you can get a temp IR gun at Harbor Freight for like $20. Since the CEL won't tell you how bad the cats get, your only indicator now will be lack of performance, poor acceleration, sounds muffled, etc. I only say this because I've heard of it happen a number of times, some that have used a sim as well. High back pressure really puts a strain on the whole engine.
 
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