Hi, I am new and I would appreciate any help. I have a P0430 code from a CEL. I was told this is a bank II problem and that the passenger side front cat needs to be replaced. Do I need to buy new cats for the front or is there another way that is cheaper to fix this. All I want to do is be able to pass inspection for the state of MA. I heard that I can purchase an O2 simulator but I am not familiar with it. I went to an exhaust place and they said they couldn't do anything for me. Can I just replace the pipes minus the cats or do I need them to pass inspection?

Thanks.

 

I've had this before
but mine was due to swapping the headers from with cats to no cats so
i was running rich all the time, and so i had to get the O2 sim.

In your case since you have stock manifolds with the cats therefore
the only causes are:
like the said the cats could be bad(how many miles do you have on the odometer)
if its low...i doubt that, that could be the cause although its not out of the question. it could be premature failure
but the second thing is that the 02 sensors which there are 4 (3 on the manifold and 1 on the b-pipe) and one of them could be dirty where they aren't reading anymore or they have just failed completely
and third, there could be an exhaust leak.

more than likely i think its gonna be an o2 sensor failure since its only on bankII

good luck troubleshooting

oh yeah if you have emissions testing in yoiur state i dont suggest getting the o2 sim.
by installing the o2 sim, you're telling the ECU that you're always running within parameters even when you are not, that is y i went in that direction because i have no cats at all.

 

Here is some info on the sensors i got from another thread

 

I have 90k on the car. It's an 02 IS300. I don't think it's an 02 sensor. The CEL has been on for months now and my inspection is due next month. I contacted all the Lexus dealers and they are telling me that they only sell the replacement part as a pair and that it's about $1200 for the part plus installation. So there is no way to replace these with aftermarket headers and pass inspection?

 

i'm not sayin to replace your headers with aftermarket to fix the problem
i just mentioned that becasue that's the purpose of the o2 simulator.

here is another question
you say its been a month since this happened
did you get the codes reseted everytime or has it just been on the whole month?

the CEL light will not go off unless you reset it.
it could have been a one time incident that caused the CEL to go on.

if you havnt reset the code do that first and see how long it takes for the light to come back on
if does it again reset it a couple more times. if the light goes on almost immediately then it MIGHT be the cats but if it takes a while like a 30min to a few hours of driving then its probably just a sensor

its also cheaper to replace the o2 sensors and take a look at them to see what kind of condition they are in
than to buy the cats, check if the wires burnt out? clean them off and inspect them....they could be so covered in suit and oil that that its not taking the proper reading anymore.
you can go on ebay and search for the vendor (justisparts) they sell them cheap.
cuz right now i think you're only having problem with one bank in which it is probably the sensor.

now once you have done this and you're 100% sure that its the cats
there is a short term fix so that you can pass emssions testing....

the day b4 inspection pull out the headers, stuff some fiberglass infront of the cats not behind and let it run for a bit and the next day drive it to inspection. don't stuff so much that you suffocate the engine, try to equal it out between the Bank1 cat and bank2 cat.

your performance will drop a bit but the fiberglass should get burnt out in another couple of days.

 

Thanks for the info. I have had the CEL reset about 3 or 4 times. The CEL has come back on everytime. It takes about a half hour of driving before it comes back. I will try and check the o2 sensors and see if they are dirty. The reason I think it's the cat is because the car runs a little sluggish. I did see an ebay listing for both parts. I think I am also going to check out junk yards and see if they have them too.

Thanks again.

Rob

 

good luck bro
hope its nothing serious or costly
and study up for that exam so you pass
the inspection exam that is =)

 

The o2 sensors usually go before the cats do. they tell the ECU how the car is running so it can make adjustments, if your car is sluggish the sensors could be just as much the culprit as the cats. If either are bad, of course the light is going to come back on, resetting doesn't fix anything.

just because the o2 looks clean, doesn't mean it's in working condition.

I dunno about Mass, but here in Ca, they don't allow junkyards to sell used cats. Besides ~$70 for an o2 sensor that is pretty easy to replace vs finding a used header with good cats or buying a new one from the dealer + time and effort (or cost) to install ...

 

Sorry to bump this thread, but does the passenger seat and carpet have to removed to replace this bank 2 sensor 2 02?