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Discussion Starter · #1 ·
I got a check engine light, took it to my mechanic today and he told me that he got codes P0420 and P0430, catalytic converter efficiency low on banks 1 and 2. I recently installed an K&N FIPK a couple of weeks ago but I also passed SMOG just a couple of days before the CEL. I also had an Apex'i World Sport 2 cat-back exhaust installed a couple of months ago as well.

My mechanic suggested I put back my original intake setup and go from there. Could the FIPK be the cause? Any suggestions?

Thanks in advance!
 

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Discussion Starter · #3 ·
You don't have an aftermarket header correct? Did you disconnect your battery to reset the ecu after you installed your fipk?
Nope, no aftermarket headers installed.

But yes, I disconnected the battery for over an hour or so after I installed the intake. I didn't pump the brakes or anything afterwards though, just simply disconnected it and left it alone for a while.

I'll reset the ECU again (if my mechanic hasn't already done it already when I pick it up later today) and see what happens then.
 

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I got a check engine light, took it to my mechanic today and he told me that he got codes P0420 and P0430, catalytic converter efficiency low on banks 1 and 2. I recently installed an K&N FIPK a couple of weeks ago but I also passed SMOG just a couple of days before the CEL. I also had an Apex'i World Sport 2 cat-back exhaust installed a couple of months ago as well.

My mechanic suggested I put back my original intake setup and go from there. Could the FIPK be the cause? Any suggestions?

Thanks in advance!
sorry for derailing, but could you post a video of your setup? i'm doing the same setup, but missing the exhaust and would like to know how it sounds.
 

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The intake wouldn't cause those 2 codes. Do you know anyone with a scan tool? Your o2 sensors could be on the way out.
 

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Discussion Starter · #6 ·
The intake wouldn't cause those 2 codes. Do you know anyone with a scan tool? Your o2 sensors could be on the way out.
I replaced one of my o2 sensors maybe about 20K-30K miles ago, I don't think that might be the case.

Well anyways, the ECU was reset and the CEL came on again about a week and a half later. For now I switched back to my stock intake this morning and reset the ECU again, we'll see how it goes...if the CEL comes back I guess I'll have to get a new cat =( But I guess after that I can put on my FIPK back again.

If anything I found this thread for some extra insight:

http://my.is/forums/f93/02-is300-catalytic-converter-problems-already-332062/
 

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A p0420 or p0430 won't be set from a bad sensor. Those codes can only be set by failing/lack thereof catatlytic converters.
 

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I'm in the same boat buddy. I've been to autozone twice & reset the code twice w/ the obd2 scan tool. I was getting P0420 I was told it's the cataylist effciency below threshold & it's the catalytic converter. My questions is though does the whole header need replacing or y-pipe? I'm running stock intake, headers, y-pipe with an axle back 5zigen exhaust. I don't smell that rotten egg smell associated w/ a clogged catalytic converter though... How many catalytic converters does our IS300 have? Is it 3? Any ideas?
 

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P0420: cat system below threshold (bank 1). P0430: cat system system below threshold (bank 2). You have 3 areas to check: leakage on the exhaust system, O2 sensors & the 3 way cat.
You need a Lexus scan tool or an OBDII scan tool to check the waveform of the O2 sensors before and after the cat to see if the catalyst has deteriorated. If your cat is function properly the air/fuel ratio feedback of the O2 sensor before the cat changes from rich to lean and the feed back of the O2 sensor after the cat changes from rich to lean much more slower. But if the waveforms are are at a similar rate, then your cat has deteriorated.

Make sure there are no other code besides those 2. Then check for leakage in the exhaust system, repair or replace, if everything is ok. Then check the O2 sensors, repair or replace, if the sensors are good. then your 3 way cat is no good.

Good luck.
 

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I hate to bump an old thread but ever since I put my k&n intake on I've had the code po430 and just recently got the po420 and was wondering what to do, I can't afford anything drastic right now but any insight would be greatly appreciated.
 

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I hate to bump an old thread but ever since I put my k&n intake on I've had the code po430 and just recently got the po420 and was wondering what to do, I can't afford anything drastic right now but any insight would be greatly appreciated.
As mentioned earlier, the intake or any intake would not cause catalytic convertor efficiency codes. are there any other pending codes? have you tried resetting the codes to see if they return?
 

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Check if you have the sensor that plugs into a cylinder shaped peice with 2 vaccum tubes going from it is plugged in. Forgot what its called. Has a vaccum tube going into it from the intake and out of it going toward the rear of the engine
 

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Check if you have the sensor that plugs into a cylinder shaped peice with 2 vaccum tubes going from it is plugged in. Forgot what its called. Has a vaccum tube going into it from the intake and out of it going toward the rear of the engine
that's the canister closed VSV for the evap system. unfortunately that wouldn't be the case if there was an issue there because he would get an emissions code similar to codes P044X.
 

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I swear my friend got those 2 codes on his is after I installed his intake and forgot to plug that sensor back in lol... (It was 2am was tired). He got a check engine couple days later. Told him to come by, I brought out the obd reader and it said its the cats... I was like how the f*** is that possible, rechecked my work and forgot to plug the sensor into the canister closed vsv. No check engine light ever since then. Just my input...
 

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Where is this located? And I only get a cel I'd say after two weeks of driving or one long distance trip. If I got obx headers and token solutions o2 delete would that solve all issues? I thought about going back to stock intake however I like the look of the fipk in the engine bay.
 

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Where is this located? And I only get a cel I'd say after two weeks of driving or one long distance trip. If I got obx headers and token solutions o2 delete would that solve all issues? I thought about going back to stock intake however I like the look of the fipk in the engine bay.
yes, if you use an O2 sim, then it will take care of both efficiency codes. XwiLx is referring to the two wire sensor which originally is connected to the driver side of the stock air box. It's only job is to handle the emissions from the EVAP system and has a line going into it from the fuel tank and a line that 90's into the intake. It may have been a coincidence, but there's no possible way that a cat efficiency code could be thrown if there was an issue there. If you have a P0420 or P0430 DTC then you can delete those downstream sensors with a sim/delete from Tokensolutions and those codes will be eliminated.
 

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^^^^ once again all hail jasonm4444 thank you for the help
 
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It doesn't hurt to check :/ Just stating what happened to my friend and what cels popped up and disappeared after plugging in that sensor. It made no sense, but it happened.
 

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i have the same problem but my cars stock... dont get fooled ; ur cat's going bad. my mechanic told me that the o2's wont trick the cat to getting tripped off on the sensor; however it could work the other way around...

and im still driving it the way it is...
 
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