catalyic converter problem

antonio fuller

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Ok so when I bought this last 2006 LS it need new coils I didn't have the money so I had to just drive it awhile with the bad ones this caused fuel to get in the converter and blow it out
I usually run all OE parts but the converters don't come apart from the exhaust from the factory and its over 2k for the system so I went the cheap way had the converters cut and stuck two cheap ones in. This fixed my problem so I thought but now the check engine light comes on after the car has been parked for the day the next day the light is off. I didn't change the sensors and my question is should I change the sensors are is it a issue with the converters I replaced it with


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Downstream sensors are doing their job, why shoot the messenger?

Let me guess ... P0420 or 430 ??? (I think)

You're running too rich, clean the MAF sensor. Check for vacuum leaks and be sure your new coils and plugs are good. It's dumping too rich of a fuel/air mix into the CAT's

It could of course be faulty O2 downstream sensors on either bank, you'd have to take some readings to be sure or simply get the parts cannon out and try your luck.

Possibly ... of course
 
aftermarket cats aren't going to be telling the downstream o2's that they
are doing a factory level job at scrubbing the exhaust.

if you have a local tuner, you can have them turn the rear o2's off, and
your codes will go away. you will need to check your states inspection
details and make sure on how many not ready's you can have.
 
??????

The cats don't tell the o2 sensors anything. All the downstream o2 sensors do is read unburned fuel. Cheap cats have less platinum... so do a less better job of cleaning up unburned fuel. The downstream o2 sensors are probably doing their job correctly,,, and the cheap cats are probably at fault like Antonio suspects.
 
??????

All the downstream o2 sensors do is read unburned fuel. Cheap cats have less platinum... so do a less better job of cleaning up unburned fuel. The downstream o2 sensors are probably doing their job correctly,,, and the cheap cats are probably at fault like Antonio suspects.

that's exactly what i'm saying. hello.
 
Hello!!! Haha, lot of that going around these days, now that the garbage has been taken out, we need to get back to properly understanding and helping one another.

+1
 
still getting a CEL after replacing cats with aftermarket just like almost every other person that has done the same...

#ParForTheCourse



long story very short, cheap parts often do not function nearly as well as OEM parts. this is often very important when a part is required to operate with in a certain measured tolerance.
 
I have always wondered, if you had to go on the cheap for a cat replace, wouldnt it be better to go to a junkyard and find a low mileage unit?

Crossing my fingers on mine that the original owner didnt do any harm....
 
From what I recall, used parts resellers cannot sell you used cats. Best bet would be to find someone parting one out, even though that is probably still illegal to sell them that way as well.
 
Figures. I know they steal them all the time here in CA, so must be a market for them, at least the melt down version. Easy way to get around any law though is buy a junker, swap its cats, take to junkyard. :cool: Your the owner of two vehicles at one point, they cant say word one or likely even prove you did it.
 
wouldnt it be better to go to a junkyard and find a low mileage unit?

with the extremely high rate of coil failure on the LS, I would expect most cats pulled from junked out cars would at least have some damage to them if not completely gone already.
 
with the extremely high rate of coil failure on the LS, I would expect most cats pulled from junked out cars would at least have some damage to them if not completely gone already.

Rite I wouldn't do the work getting it out install etc just to find out its bad are bad two months later


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Is there a formal way to test if your cat is already damaged? What are your options besides paying $2k for new ones?
 
Is there a formal way to test if your cat is already damaged?

if car doesn't have a CEL on, then cats are within OEM specifications. if CEL points to cats and its not a sensor issue, then your cats are most likely not within OEM specifications.

aside from that you can have your emissions system tested (assuming of course that the rest of the engine is in tip top shape)

What are your options besides paying $2k for new ones?

options

1, do nothing and hope it doesn't get bad enough(clogged) to completely choke out the engine, then live with CEL being on*

2, hollow out clogged cat, then live with CEL being on*

3, buy cheaper aftermarket cats and hope your one of the lucky few that it works and keeps the CEL off, or possibly live with CEL being on*

4, buy $2k OEM cats that will work perfectly fine until next case of coil failure which then may damage them and start the whole problem over again.




* If CEL is on, and you live in an inspection state, then this is most likely not an option for you.
 
If you buy aftermarket cats, go to a local tuner and have them turn the rear o2 sensors off. As long as you can have at least 1 not ready, your good.
 
if car doesn't have a CEL on, then cats are within OEM specifications. if CEL points to cats and its not a sensor issue, then your cats are most likely not within OEM specifications.

aside from that you can have your emissions system tested (assuming of course that the rest of the engine is in tip top shape)



options

1, do nothing and hope it doesn't get bad enough(clogged) to completely choke out the engine, then live with CEL being on*

2, hollow out clogged cat, then live with CEL being on*

3, buy cheaper aftermarket cats and hope your one of the lucky few that it works and keeps the CEL off, or possibly live with CEL being on*

4, buy $2k OEM cats that will work perfectly fine until next case of coil failure which then may damage them and start the whole problem over again.




* If CEL is on, and you live in an inspection state, then this is most likely not an option for you.

Lmao right got to love this car smdh


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