Need advice on Catalytic Converter

Speed777

Speed777

Greenie N00B Member
Greenie Member
I recently got a check engine code P0421 warm up catalyst efficiency below threshold(bank1)
which has to do with catalytic converter according to my mechanic. I first tried pouring a bottle of cataclean
to a full tank of gas to see if this helped clean the cat but unfortunately got code back again.
I have a cobb catted dp for about 7 years now and it has come the time to replace cat so that being said i came across these 3 brands and I'm wondering if any of you have had any experience with these products. GESI cat is out of the equation due to being to expensive , it cost almost like buying a new cobb dp. These 3 below are way cheaper cost wise.
I've been considering 3 products:
https://zzperformance.com/products/catalytic-converters?variant=12623019278447
https://www.burton-racing.com/produ...talytic-converter?_pos=1&_sid=962c8ef7b&_ss=r
https://www.holley.com/products/exhaust/catalytic_converter/49_state/universal/parts/2000130

Can anybody let me know if you have had any previous experience with any of these that can share some light here? all 3 are 200 cell count like the one that came with the DP.
I need to cut out old cat from dp and weld new cat. Thanks in advance for the help.
 
Holley has a good rep in general in the racing world afaik. It's the only brand I recognize I dunno man pick one and send it. We're sure it not just the o2 sensor?
 
OP if you do decide to go with an O2 sensor I would recommend the NGK/NTK brand.

Also if you decide to swap the cat I would see if Magnaflow offers anything if you don't want to get the GESI.

I would start with the O2 sensor though as Awa and EB mentioned.
 
Thanks to all of you for kindly sharing your help.
I told my mechanic about the possibility of being oxygen sensor but he told me when its oxygen sensor its a different code and that its mentioning a temp problem of cat not reaching the adecuate heating temp. He told me that when oxygen sensor fails, the codes are different.

P0135: oxygen sensor in front of the catalytic convertor 1, heating circuit / open. P0175: system too rich (bank 2) P0713: fuel trim malfunction (bank 2) P0171: system too lean (bank 1)
trust me i thought the same as you guys but thats the answer i got from him
So thats why im considering the cat.
So brand wise flowmaster?

Mtnbker3531 said:
OP if you do decide to go with an O2 sensor I would recommend the NGK/NTK brand.

Also if you decide to swap the cat I would see if Magnaflow offers anything if you don't want to get the GESI.

I would start with the O2 sensor though as Awa and EB mentioned.
Click to expand...

Thanks. The magnaflow high flow 200 cell cat goes for $735.00, just to much money.

What ngk oxygen sensor model did you purchase?
 
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When is the last time you got the car hot and beat on it to "blow the cobwebs out"
 
I'm having the same issue with the COBB catted downpipe.

First I got a P0421 CEL code, so I tried the O2 extender with no luck (now I have a P0137 CEL code "O2 Sensor Circuit Low Voltage"). I have also replaced the bank 2 O2 sensor twice. Still the same codes with/without the O2 extender.

I've heard that replacing the cat doesn't work, but before going back to stock, hopefully you found a solution with the cat replacement. Any news on this?
 
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