LS1GTO.com Forums banner

1 - 14 of 14 Posts

·
Registered
Joined
·
24 Posts
Discussion Starter #1
Installed hi flow cats a few weeks ago and had no problems. Last night the P0430 catalyst code popped up. Im assuming its the mid pipes causing this... seems like im going to need to tune out the rear O2’s...

In the meantime is the computer pulling timing? Am i on the right track assuming its the midpipes. Thanks!
 

·
Registered
Joined
·
884 Posts
Yup. Tune them out or get 02 sensor extenders which pull the sensor out of the air stream some to trick the computer to think it’s normal.
No ecm changes are made using rear O2 input values, just confirms cat efficiency.
 

·
Registered
Joined
·
24 Posts
Discussion Starter #3
Yup. Tune them out or get 02 sensor extenders which pull the sensor out of the air stream some to trick the computer to think it’s normal.
No ecm changes are made using rear O2 input values, just confirms cat efficiency.
Cool. I figured this was the case. I was lucky with my wife's car... JBA headers and JBA mids with no problems on an R/T charger, So I went the same route with the goat. But alas- a different result.
 

·
Registered
Joined
·
884 Posts
Hence why I have to put on stock cats for smog purposes, haven’t bought the software and smog guy actually looks under my car.
 

·
Registered
Joined
·
24 Posts
Discussion Starter #5
Hence why I have to put on stock cats for smog purposes, haven’t bought the software and smog guy actually looks under my car.
Im lucky they don't do that in Texas. But couldnt you get by with high flows? I mean TECHNICALLY there are cats still.?
 

·
Registered
Joined
·
884 Posts
True but not CARB certified. All performance enhancing products need to be vetted by CARB and get an EO # to show compliance. There are supercharger kits that are legal but long tubes for example are not.
I could pass the visual inspection if the smog tech doesn’t get up close and personal and look for an actual serial # on the cat, which would be hard to do from the ground. I’d just have to do it before the code gets set.

you’ll also notice that vendors won’t ship certain parts because of this or specify for off road use only.
 

·
Registered
Joined
·
9 Posts
As long as they dont smog in your state. Spark plug non foulers the way to go.
No cats on mine and I passed inspection.
 

·
Registered
Joined
·
9 Posts
I am running a custom tune. The tuner turned the rear O2’s to “not supported”
You see any mpg gains from that tune?
I had a goat back in the day tuned with biggish cam getting same mpg on hwy as I'm getting with my new goat that only has cai and mufflers without cats, stock manifolds.
 

·
Registered
Joined
·
24 Posts
Discussion Starter #12
You see any mpg gains from that tune?
I had a goat back in the day tuned with biggish cam getting same mpg on hwy as I'm getting with my new goat that only has cai and mufflers without cats, stock manifolds.
Not sure. I do not daily the car, its a weekend fun car. So mpg is least of my concern.
 

·
Registered
Joined
·
24 Posts
Discussion Starter #13
You see any mpg gains from that tune?
I had a goat back in the day tuned with biggish cam getting same mpg on hwy as I'm getting with my new goat that only has cai and mufflers without cats, stock manifolds.
Also If the “not supported” route doesnt work for inspection this month then i will get the tuner to turn them back on, and i will go the anti fouler route
 

·
Registered
Joined
·
300 Posts
You will likely soon be getting the 420 as well (one is left bank the other right) Aftermarket hi flows generally look more like a glass pack straight thru than a cat. The ecm looks at the upstresam temp compaired to the down, if it doesn't see a change of @100 degrees it sets that code. Other than turning the fault light on it doesn't hurt anything; the down stream o2 measures the efficiency of the converter, that is all.
 
1 - 14 of 14 Posts
Top