SES Light - cat needs to be replaced?
SES Light - cat needs to be replaced? So I'm getting an SES light, P0420 and P0430. 1st bank and second bank, IIRC.
Does this mean the cat(s?) are bad? I had an open exhaust after the cat for a while. could that cause it to throw the code, or do i have to replace the cat? and is there more than one? I was under there fixing the pipe on my exhaust and i didn't see a 2nd one...
Thanks in advance.
Car is a 96 TA, LT1 + T56
Does this mean the cat(s?) are bad? I had an open exhaust after the cat for a while. could that cause it to throw the code, or do i have to replace the cat? and is there more than one? I was under there fixing the pipe on my exhaust and i didn't see a 2nd one...
Thanks in advance.
Car is a 96 TA, LT1 + T56
Teching In
Joined: Mar 2008
Posts: 6
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From: Los Angeles, California
I've always had open exhaust and never cause me to throw a code, more then likely its your 02 sensors, if it was your cats you would notice a lot of hesitation everytime you step on the gas and wouldnt be able to go above 3k rpms.
P0420 and P0430 are catalytic converter codes. The cats need to be replaced. Or just cut off.
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Staging Lane
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if you have access to an inferred temperature gun you can see if the cats are clogged or not. if you point the gun b4 the cat (with the car on) and get a temp reading and then point the gun after the cat and get that temp reading the temp behind the cat should be hotter than b4 it.
Well, cleared the codes with my new OBD2 scanner, took it for a spirited drive and the SES light hasn't come back yet... Guess it was because of the open exhaust. no backpressure, or readings that were off due to the oxygen or something is my guess. cheap fix for sure!
ok so i lied. SES light came back.
So is it definitely the 2 cats, or could it be a sensor?
If it is the cats, what is the most beneficial, but not exorbitantly expensive way to fix it and still pass emissions? I figure if I can upgrade for the same price as replacing all the upper pipe, i might as well.
So is it definitely the 2 cats, or could it be a sensor?
If it is the cats, what is the most beneficial, but not exorbitantly expensive way to fix it and still pass emissions? I figure if I can upgrade for the same price as replacing all the upper pipe, i might as well.
The options would be to get direct fit replacements, get aftermarket cats (I have heard someone mention the Magnaflow part # 59959) and have them welded in, or gut the cats and have someone with a programmer remove the codes for bad cats. Since you car is OBDII you can pass emissions as long as the codes are tuned out. It's illegal, of course. 
P.S. I love Quasar Blue LT1s, got any pics of it?
Edit: I found your other thread with the picture. Looks great. One of those weird TA's with the Formula spoiler.
P.S. I love Quasar Blue LT1s, got any pics of it?
Edit: I found your other thread with the picture. Looks great. One of those weird TA's with the Formula spoiler.
Last edited by Formula413; Oct 1, 2008 at 10:32 PM.
The options would be to get direct fit replacements, get aftermarket cats (I have heard someone mention the Magnaflow part # 59959) and have them welded in, or gut the cats and have someone with a programmer remove the codes for bad cats. Since you car is OBDII you can pass emissions as long as the codes are tuned out. It's illegal, of course.
P.S. I love Quasar Blue LT1s, got any pics of it?
Edit: I found your other thread with the picture. Looks great. One of those weird TA's with the Formula spoiler.
P.S. I love Quasar Blue LT1s, got any pics of it?
Edit: I found your other thread with the picture. Looks great. One of those weird TA's with the Formula spoiler.
Sounds good. I figured those were my options, but I don't have a tuner so I'll probably just get a couple of cats and have them welded in because i have to get another piece of exhaust welded too. though one thing on the Magnaflow cats... Jegs list them as only suitable for cars up to 5.2l of displacement, its there going to be a flow issue on the LT1? I just don't want to rape the power if i don't have to.
I did some more digging around, the part number I listed is for a 3" in/out universal cat. I'm not sure what size inlet/outlet the stock cats on an LT1 have, I know the I pipe is 2 1/2", I think the cats might be too but I'm not sure. Here is a page listing all the sizes and shapes available for that cat:
http://www.planetmagnaflow.com/shop/Spun-Cat-100.html
Magnaflow also makes direct fit replacements which they claim flow better than stock, and they aren't very expensive. Try looking around online, the site I listed above didn't have them but they are available. Part numbers are 23517 = driver side, 23518 = passenger side.
http://www.planetmagnaflow.com/shop/Spun-Cat-100.html
Magnaflow also makes direct fit replacements which they claim flow better than stock, and they aren't very expensive. Try looking around online, the site I listed above didn't have them but they are available. Part numbers are 23517 = driver side, 23518 = passenger side.
