P0430 code
Thread Starter
Melting Slicks
Joined: Jan 2017
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From: CONCORD CA.
P0430 code
not sure if i've ran this out before ( if so, my apologies ). i've had a P0430 code for quite a while now ( since last 11/2021 ). i've replaced the downstream O2 sensor & passenger side cat.
i ran a live data check this morning:
Cat 1 was @ 1054.4°F, Cat 2 @ 982.°F.
O2 sensor readings:
B1S1 (V): .755
B1S2 (V): .720
B2S1 (V): .825
B2S2 (V): .735
does any of this point to any issues? any ideas of what else to look for? i've put on about 5k miles and the car feels fine ( no noticeable loss in power or mpg ).
i ran a live data check this morning:
Cat 1 was @ 1054.4°F, Cat 2 @ 982.°F.
O2 sensor readings:
B1S1 (V): .755
B1S2 (V): .720
B2S1 (V): .825
B2S2 (V): .735
does any of this point to any issues? any ideas of what else to look for? i've put on about 5k miles and the car feels fine ( no noticeable loss in power or mpg ).
Team Owner
Joined: May 2000
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From: Plantation Florida USAF(Retired) 1966-1990
U.S. Air Force
St. Jude Donor '05 thru '26
NCM Sinkhole Donor
Have you measured with thermometer laser how hot your Cats are getting, any muffler shop will do it for you for free, thinking there get the job.
When I had right Cat, with check engine light, the temperature was above 400 degrees, and the left was cool temperature.
My car was 2005 at the time with 73,000 miles.
When I had right Cat, with check engine light, the temperature was above 400 degrees, and the left was cool temperature.
My car was 2005 at the time with 73,000 miles.
Thread Starter
Melting Slicks
Joined: Jan 2017
Posts: 2,697
Likes: 890
From: CONCORD CA.
Have you measured with thermometer laser how hot your Cats are getting, any muffler shop will do it for you for free, thinking there get the job.
When I had right Cat, with check engine light, the temperature was above 400 degrees, and the left was cool temperature.
My car was 2005 at the time with 73,000 miles.
When I had right Cat, with check engine light, the temperature was above 400 degrees, and the left was cool temperature.
My car was 2005 at the time with 73,000 miles.
Team Owner
Joined: May 2000
Posts: 53,601
Likes: 5,591
From: Plantation Florida USAF(Retired) 1966-1990
U.S. Air Force
St. Jude Donor '05 thru '26
NCM Sinkhole Donor
I saw go to Muffler shop, that's what they do for living, and your Passenger side is hot, and blocked?
Thread Starter
Melting Slicks
Joined: Jan 2017
Posts: 2,697
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From: CONCORD CA.
Safety Car
Joined: May 2016
Posts: 4,633
Likes: 1,818
From: Erlanger, Kentucky
There are a number of things that can cause a P0430. Cat going bad for sure but base on the temps, I doubt its your cats.
Check your air intake and your intake clamps to make sure everything is seated and sealing. Loose intake manifold can leak and cause problems. Leaking exhaust also can cause this so check exhaust gaskets, header or manifold bolts for looseness, check connections in the exhaust. O2 sensors can sometimes get loose and back out which can cause this code.
P0430 is a code for the cat on the passenger side and if that was replaced, I would bet you have a leak in the exhaust system somewhere on that side.
Check your air intake and your intake clamps to make sure everything is seated and sealing. Loose intake manifold can leak and cause problems. Leaking exhaust also can cause this so check exhaust gaskets, header or manifold bolts for looseness, check connections in the exhaust. O2 sensors can sometimes get loose and back out which can cause this code.
P0430 is a code for the cat on the passenger side and if that was replaced, I would bet you have a leak in the exhaust system somewhere on that side.
Thread Starter
Melting Slicks
Joined: Jan 2017
Posts: 2,697
Likes: 890
From: CONCORD CA.
There are a number of things that can cause a P0430. Cat going bad for sure but base on the temps, I doubt its your cats.
Check your air intake and your intake clamps to make sure everything is seated and sealing. Loose intake manifold can leak and cause problems. Leaking exhaust also can cause this so check exhaust gaskets, header or manifold bolts for looseness, check connections in the exhaust. O2 sensors can sometimes get loose and back out which can cause this code.
P0430 is a code for the cat on the passenger side and if that was replaced, I would bet you have a leak in the exhaust system somewhere on that side.
Check your air intake and your intake clamps to make sure everything is seated and sealing. Loose intake manifold can leak and cause problems. Leaking exhaust also can cause this so check exhaust gaskets, header or manifold bolts for looseness, check connections in the exhaust. O2 sensors can sometimes get loose and back out which can cause this code.
P0430 is a code for the cat on the passenger side and if that was replaced, I would bet you have a leak in the exhaust system somewhere on that side.
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Thread Starter
Melting Slicks
Joined: Jan 2017
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From: CONCORD CA.
Leaks around the intake will NOT cause a P0420/0430...do your downstream O2 sensors switch or oscillate like the upstream...they should not...front should not look like the back !!...when the cats are hot and at 3000 RPM they should be steady anywhere from 700-800mV...you may have an exhaust leak somewhere...I use a shop-vac with the outlet hose switched around so it blows out...you can use a soapy water solution to find the leak.
https://youtu.be/zQ8BXAwK-QY
https://youtu.be/zQ8BXAwK-QY
thanks the info.
Thread Starter
Melting Slicks
Joined: Jan 2017
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From: CONCORD CA.
Burning Brakes
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From: Florida
Another thought, was the replacement cat a factory or factory equivalent or some kind of cheap aftermarket? Some O2 sensors are just on the boundary line for working with a stock cat but an aftermarket that isn't well designed or flows considerably more than factory may trip it. When I replaced the downpipe on my old 02 Grand Prix GTP I had installed a ZZP high flow catted downpipe and was getting a code for a faulty cat, when I took it to the shop they checked and said it was a weak 02, replaced with a new AC Delco and problem went away.
Thread Starter
Melting Slicks
Joined: Jan 2017
Posts: 2,697
Likes: 890
From: CONCORD CA.
[QUOTE=C6VetteLover;1605341336]Another thought, was the replacement cat a factory or factory equivalent or some kind of cheap aftermarket? Some O2 sensors are just on the boundary line for working with a stock cat but an aftermarket that isn't well designed or flows considerably more than factory may trip it. When I replaced the downpipe on my old 02 Grand Prix GTP I had installed a ZZP high flow catted downpipe and was getting a code for a faulty cat, when I took it to the shop they checked and said it was a weak 02, replaced with a new AC Delco and problem went away.
i had the code prior to the cat install. even after the install, the CEL remained. initially i replaced the downstream O2 sensor, then the cat. i still haven't ran live data under load but, at idle, all 4 sensors, are within mV range.
I'm going to make an appointment within the next week, to get into the muffler shop. have him snoop around checking for exhaust leaks. at this time, this seems the most likely culprit.
i've got till December to figure it out ( registration and smog test ).
i had the code prior to the cat install. even after the install, the CEL remained. initially i replaced the downstream O2 sensor, then the cat. i still haven't ran live data under load but, at idle, all 4 sensors, are within mV range.
I'm going to make an appointment within the next week, to get into the muffler shop. have him snoop around checking for exhaust leaks. at this time, this seems the most likely culprit.
i've got till December to figure it out ( registration and smog test ).
Advanced
Joined: Sep 2021
Posts: 59
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From: Charleston, WV
Leaks around the intake will NOT cause a P0420/0430...do your downstream O2 sensors switch or oscillate like the upstream...they should not...front should not look like the back !!...when the cats are hot and at 3000 RPM they should be steady anywhere from 700-800mV...you may have an exhaust leak somewhere...I use a shop-vac with the outlet hose switched around so it blows out...you can use a soapy water solution to find the leak.
https://youtu.be/zQ8BXAwK-QY
https://youtu.be/zQ8BXAwK-QY
Hold on. You push air up muffler to check leaks? Damn thats a good idea, sob..
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Joined: May 2000
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From: Plantation Florida USAF(Retired) 1966-1990
U.S. Air Force
St. Jude Donor '05 thru '26
NCM Sinkhole Donor
[QUOTE=cgladish;1605341376]
Any updated yet, the rest are interested in your finding.
Another thought, was the replacement cat a factory or factory equivalent or some kind of cheap aftermarket? Some O2 sensors are just on the boundary line for working with a stock cat but an aftermarket that isn't well designed or flows considerably more than factory may trip it. When I replaced the downpipe on my old 02 Grand Prix GTP I had installed a ZZP high flow catted downpipe and was getting a code for a faulty cat, when I took it to the shop they checked and said it was a weak 02, replaced with a new AC Delco and problem went away.
i had the code prior to the cat install. even after the install, the CEL remained. initially i replaced the downstream O2 sensor, then the cat. i still haven't ran live data under load but, at idle, all 4 sensors, are within mV range.
I'm going to make an appointment within the next week, to get into the muffler shop. have him snoop around checking for exhaust leaks. at this time, this seems the most likely culprit.
i've got till December to figure it out ( registration and smog test ).
i had the code prior to the cat install. even after the install, the CEL remained. initially i replaced the downstream O2 sensor, then the cat. i still haven't ran live data under load but, at idle, all 4 sensors, are within mV range.
I'm going to make an appointment within the next week, to get into the muffler shop. have him snoop around checking for exhaust leaks. at this time, this seems the most likely culprit.
i've got till December to figure it out ( registration and smog test ).
Thread Starter
Melting Slicks
Joined: Jan 2017
Posts: 2,697
Likes: 890
From: CONCORD CA.
[QUOTE=1bdvet;1605373471]assuming that this was directed to the OP but, i also had a comment embedded within that message too ( second half of the note ).
in case it to me, I'm still waiting to get the car into the shop for an overview.
if your note was to OP, I'll, just wait on the sidelines.
in case it to me, I'm still waiting to get the car into the shop for an overview.
if your note was to OP, I'll, just wait on the sidelines.