2003 P5 replacing cat with header.

stanger9410

Member
:
Mazda Protege 5
I've got an 03 P5 with 180k on it. I got the P0421 code amd need to fix it so I can sell it. I have the thought to just put a new header on and remove the cat all together. What do I need to do to get the CEL to stay off after the front cat is gone? I've seen talk of the spark fouler trick or something of the sort? Im also considering knocking all the crap out of the cat but I would still need to do the non fouler trick. Any advice?
 
What do I need to do to get the CEL to stay off after the front cat is gone?

Talk to the next potential owner and figure it out together.

They keep track of VINs ya know,... how do ya think I found out that my rear calipers were just done before new ones were sold to me,..

(I've seen talk of little bolt hiding a little screw or something of the sort?)
 
I've got an 03 P5 with 180k on it. I got the P0421 code amd need to fix it so I can sell it. I have the thought to just put a new header on and remove the cat all together. What do I need to do to get the CEL to stay off after the front cat is gone? I've seen talk of the spark fouler trick or something of the sort? Im also considering knocking all the crap out of the cat but I would still need to do the non fouler trick. Any advice?

I run a 4-2-1 header with no garbage can at the front, just a small cat in secondary position, which more than takes care of stringent Colorado emissions. If the cat's burned out, trying to empty it won't make a difference. My new cAt cost around $125 plus installation. As for non-fouler, didn't work for me. Or as has been stated, negotiate with buyer.
 
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So how many people out there sold their P5 with a header and told the new owner about your trick ??

That's part of the transfer of ownership agreement,...

I'm almost done my non-fouler trick myself,... Just have to install it,... I'm in no rush though,... My pre-cat is working perfectly (seafoam and all,...)

I'm in it for investigational purposes only. (gotta figure out that magic box,... AKA ECU)
 
All I did was install my 4-1 header & use the MSP o2 extension cable, welded in a bung after my second cat. Haven't had any problems passing emissions
 
Leave the original emissions related equipment intact and sell it as is for a bit less. This way if it end up being difficult to fix, you didn't waste money or time messing around... no liability for modifying the emissions control equipment for either of you.
 
I did the non fouler trick and my CEL is cleared. The buyer told me to fix the light, so i did. he understands the cat could be a problem in the future, but there is no issue with the car running at all. im not worried about it, and he doesnt seem to be either....
 
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