001Stunna
Well-Known Member
I'll go ahead and predict the future. He will put it on and the p0420 code will go away and not come up anymore and his rear o2 sensor will read a flat .4-.5v no matter what.
Car threw a code.
- Thread starter 00Txcoupe
- Start date
I'll go ahead and predict the future. He will put it on and the p0420 code will go away and not come up anymore and his rear o2 sensor will read a flat .4-.5v no matter what.
LeBirdNest
Titleist
So, i used the cat gasket and reamed the holes a bit 
to fit the top of th j pipe flange and no more leak. \m/... I put the non fouler at the cat's o2 and went through three start/drive/shut offs, (roughly 30 miles) no CEL but i dont think im out of the woods yet. Just an update.
to fit the top of th j pipe flange and no more leak. \m/... I put the non fouler at the cat's o2 and went through three start/drive/shut offs, (roughly 30 miles) no CEL but i dont think im out of the woods yet. Just an update.
LeBirdNest
Titleist
Well, I had stated in the Box that I had thought I blew the gasket already, turns out as a coincidence that a weld on my piping back near the muffler punctured. 
So ill have to get that fixed.
In news with the flange leak and P0420 code. Like stated before, I repaired the gasket and it works great! Also backed the o2 sensor out and so far no code. I will be driving a good amount on the highway today so fingers crossed it doesn't come back after that.
So ill have to get that fixed. In news with the flange leak and P0420 code. Like stated before, I repaired the gasket and it works great! Also backed the o2 sensor out and so far no code. I will be driving a good amount on the highway today so fingers crossed it doesn't come back after that.
LeBirdNest
Titleist
Alright so after 9 starts/drives/shut offs, 75 miles under 45 mph and roughly 45 hghwy miles over 70 mph, at 118 miles the CEL p0420 came back on.
Things ive done:
Fixed leak
Backed out CAT o2 sensor with nonfouler
Keep in mind i have a highflow CAT.
Things I havent done:
Replaced CAT o2 sensor
Put original CAT back on.
Things ive done:
Fixed leak
Backed out CAT o2 sensor with nonfouler
Keep in mind i have a highflow CAT.
Things I havent done:
Replaced CAT o2 sensor
Put original CAT back on.
001Stunna
Well-Known Member
Add the second fouler
...even though you'd be the first needing to use it aside from people running test pipes.
LeBirdNest
Titleist
I dont think ill have room for the second fouler. Lol
If that doesnt work, what will?
If that doesnt work, what will?
LeBirdNest
Titleist
That doesnt seem legit
I need also to consider that my car is ACTUALLY running rich and the a/f ratio is messed up. The car does have 204k miles on it. So idk. This has never been an issue of mine. I mean, ill try the second fouler first but after that, im at a loss.
Edit: Goin to put the other fouler on tonight as well as reset the code by the fuse to see if that fixes anything.
I need also to consider that my car is ACTUALLY running rich and the a/f ratio is messed up. The car does have 204k miles on it. So idk. This has never been an issue of mine. I mean, ill try the second fouler first but after that, im at a loss.
Edit: Goin to put the other fouler on tonight as well as reset the code by the fuse to see if that fixes anything.
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The o2 sensor in the header is the only one that'll affect lean/rich fuel trims. The ONLY purpose the one after the cat serves is to tell the ECU that the cat is working. That's it.
I'd just sim it, and call it good. You know the cat's working. If it doesnt clear up with the 2nd plug defouler, my guess would be a bad o2 sensor.
I'd just sim it, and call it good. You know the cat's working. If it doesnt clear up with the 2nd plug defouler, my guess would be a bad o2 sensor.
LeBirdNest
Titleist
Well, the one in the CAT is black so it could mean that its okay enough to not throw the secondary o2 sensor failure code but not good enough to clear th below threshold code. Im about to put that second fouler on and drive about 30-40 miles, highway/street to see if that helped.
