P0430 and P0420
#1
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P0430 and P0420
I have had the P0430 code for almost a year now and at times the CEL has turned off for a few days. I got a smog check last November after I reset the CEL and I passed fine I guess. About a month ago I scanned the car and I have both P0430 and P0420 now. Yesterday the CEL went off again. I was planning on taking my gs300 to a shop to check for exhaust leaks to try and diagnose, but if the CEL goes off on its own then what do you think is my problem? I read on here that their might be a crack in a hose at the back of the engine but I did not see one when I inspected it.
#2
Pole Position
you answered your own question, this one has been asked a million times. Inspect the ENTIRE exhaust for leaks as this is the most probable cause. If there are no leaks then consider your O2 sensors.
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omar804 (02-18-20)
#3
Lexus Test Driver
P0430 and P0420
Get all o2 sensors and exhaust gaskets BEFORE and AFTER cat converters. Get that installed down there nice and tight and your CEL should turn off permanently. I went thru this. I paid for new cats from Sewell. But I could've taken the cheaper o2 sensor and gasket route and had the same result. I poem on having this GS430 for the long run so I had I bought new cats for that reason. Take my advice. Shouldn't be too much. Good luck brother! Let us know what happens! #GODBLESS
#4
Pole Position
Get all o2 sensors and exhaust gaskets BEFORE and AFTER cat converters. Get that installed down there nice and tight and your CEL should turn off permanently. I went thru this. I paid for new cats from Sewell. But I could've taken the cheaper o2 sensor and gasket route and had the same result. I poem on having this GS430 for the long run so I had I bought new cats for that reason. Take my advice. Shouldn't be too much. Good luck brother! Let us know what happens! #GODBLESS
#5
Instructor
iTrader: (8)
I have had the P0430 code for almost a year now and at times the CEL has turned off for a few days. I got a smog check last November after I reset the CEL and I passed fine I guess. About a month ago I scanned the car and I have both P0430 and P0420 now. Yesterday the CEL went off again. I was planning on taking my gs300 to a shop to check for exhaust leaks to try and diagnose, but if the CEL goes off on its own then what do you think is my problem? I read on here that their might be a crack in a hose at the back of the engine but I did not see one when I inspected it.
my P0420 came on 2 months ago. i reset the light and it only came back on a few days ago... i strapped the OBD2 reader to it and checked the live data on my commute to work yesterday and today... there was no codes pending on the initial cold start... but when i shut the cars off for a few mins and restarted it, P0420 went pending...
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#9
Lexus Test Driver
P0430 and P0420
I think I remember you saying you bought new cats and I was telling you to return them because you dont need them and you were like na Ill change them anyway since I am keeping this car for the long run. I guess it doesn't hurt but thats one expensive uneccesary repair lol.
#10
Lexus Test Driver
P0430 and P0420
I've been reading this whole thread. Ima be blunt my friends. 9/10 times the problem with these codes are the GASKETS THAT GO BEFORE THE CAT CONVERTERS AND THE GASKETS AFTER THE CAT CONVERTERS. It's usually air leaks anywhere by the cats that cause those codes to go off. And new o2 sensors. That fixes the problem most the time my friends believe me!
#12
Having trouble? Get a longer bar, or use a pipe from home depot/lowes/etc.
#15
Instructor
iTrader: (8)
also do i remove the nuts or the bolts? im used to seeing a stud and the nut is what secures everything, but when i looked underneath, it seemed like a nut and bolt...