ZZP 200 Cell Catted downpipe?
11-05-2013, 08:53 AM
#1
New Member
Thread Starter
Join Date: 03-23-2010
Location: Delaware
Posts: 23
ZZP 200 Cell Catted downpipe?
I am about to start ordering some parts. I was curious about the ZZP 200 cell catted downpipe. Their site makes it seem like the 400 cell cat will not cause a CEL, but doesn't describe the 200 cell. I was wondering if anybody here has experience with them to tell me if it CEL's or not.
11-19-2013, 06:23 PM
#3
Technical Moderator
Join Date: 01-23-2009
Location: Fredericksburg, Virginia
Posts: 24,671
However, many aftermarket cats will set a CEL on account of they are not made to the same standards as "from the factory". Many vendors do not represent that you will pass any emissions test.
Don't throw your OE away, you may need it for selling the car down the road.
Don't throw your OE away, you may need it for selling the car down the road.
11-19-2013, 07:30 PM
#4
Senior Member
Join Date: 04-26-2009
Location: City of Champions
Posts: 666
Keep the stock DP, but 'core' the 2nd cat, with a piece of 2.75" tubing.
You don't even have to remove the DP to do this.
This will work better than an aftermarket DP
Try it , you'll like it...
A FREE mod that works...
12.39 in the quarter mile.
30 MPG with E47 ethanol, staying out of boost, which is very hard to do.
And best of all, NO CEL
Here's why.
The stock ECM is so complex , with more tables that we will
never ever know about.
The 1st cat is very important, because some of the ECM tables,
were designed around a set amount of flow/charge pressure, in the total intake track.
This is very important at low speeds, cruising, & really in any driving mode,
when & where, no boost is present.
This is very noticeable, if you have an automatic.
Coring the 2nd cat, removes a big restriction, & at the same time, helps the
Flow thru the 1st cat.
You don't even have to remove the DP to do this.
This will work better than an aftermarket DP
Try it , you'll like it...
A FREE mod that works...
12.39 in the quarter mile.
30 MPG with E47 ethanol, staying out of boost, which is very hard to do.
And best of all, NO CEL
Here's why.
The stock ECM is so complex , with more tables that we will
never ever know about.
The 1st cat is very important, because some of the ECM tables,
were designed around a set amount of flow/charge pressure, in the total intake track.
This is very important at low speeds, cruising, & really in any driving mode,
when & where, no boost is present.
This is very noticeable, if you have an automatic.
Coring the 2nd cat, removes a big restriction, & at the same time, helps the
Flow thru the 1st cat.
11-20-2013, 10:05 AM
#5
Senior Member
Join Date: 02-13-2010
Location: HuskerNation
Posts: 698
Keep the stock DP, but 'core' the 2nd cat, with a piece of 2.75" tubing.
You don't even have to remove the DP to do this.
This will work better than an aftermarket DP
Try it , you'll like it...
A FREE mod that works...
12.39 in the quarter mile.
30 MPG with E47 ethanol, staying out of boost, which is very hard to do.
And best of all, NO CEL
Here's why.
The stock ECM is so complex , with more tables that we will
never ever know about.
The 1st cat is very important, because some of the ECM tables,
were designed around a set amount of flow/charge pressure, in the total intake track.
This is very important at low speeds, cruising, & really in any driving mode,
when & where, no boost is present.
This is very noticeable, if you have an automatic.
Coring the 2nd cat, removes a big restriction, & at the same time, helps the
Flow thru the 1st cat.
You don't even have to remove the DP to do this.
This will work better than an aftermarket DP
Try it , you'll like it...
A FREE mod that works...
12.39 in the quarter mile.
30 MPG with E47 ethanol, staying out of boost, which is very hard to do.
And best of all, NO CEL
Here's why.
The stock ECM is so complex , with more tables that we will
never ever know about.
The 1st cat is very important, because some of the ECM tables,
were designed around a set amount of flow/charge pressure, in the total intake track.
This is very important at low speeds, cruising, & really in any driving mode,
when & where, no boost is present.
This is very noticeable, if you have an automatic.
Coring the 2nd cat, removes a big restriction, & at the same time, helps the
Flow thru the 1st cat.
11-20-2013, 10:33 AM
#6
Senior Member
Join Date: 04-26-2009
Location: City of Champions
Posts: 666
400 , which is quite typical of factory GM cats.
ALSO , the stock 1st cat is much larger than the small 'soda' can
aftermarket cats, which means more surface area, which means
that the 1st cat flows very well....
Probaby flows equal to a 300 cell aftermarket 'soda' can cat.
it's also all about where the 1st cat sits, as close as possible, to the exhast manifold.
This means it will be hotter, which means that flow will be better also.
AND the ECM is programmed around this 1st cat, for excellent off idle response...
The 2nd cat is bad, very bad for good HP , torque, & throttle response...
'Coring' it, will remove the only restriction, in the stock exhaust system.
The remaining 'cat' guts will stay in place forever, as mine have stayed in
place for years...
Also this modded 2nt cat will still get hot, so if an emission inspector would happen to touch it, he will think that this cat is working correctly.
I've 'tested' this 2nd cat position with straight piping, & 'soda' can aftermarket
cats, & 'off-idle' response isn't as good as just 'coring' it.
The only cat the I have found to be equal to just 'coring' this cat, is a
big 5" diameter, $400, Random Tech 100 cell cat.
Definitely not worth it, but I had used this cat before in a 'test' DP, in which I had this as the only cat, having it welded into a catless CIA DP, in about the same position, as the 2nd cat sits.
That setup still wasn't as good as having a stock 1st cat, with a 'cored' 2nd cat.
I've spent too much time, & too much money, to only discover, that a simple 15 minute FREE mod, works best...
Last edited by 2005HHRauto; 11-20-2013 at 11:51 AM.
03-30-2014, 10:23 AM
#7
Senior Member
Join Date: 03-09-2014
Location: Wisconsin
Posts: 104
Hate to bring this up from the past,but what I get from this is coring second cat on my factory downpipe,I get no engine light,and I'll pass emissions which is important for me,and no tune mods needed?thanks sorry kinda dumb.
Was going to buy aftermarket down pipe and really don't know the benefits besides sound according to this post response.
Was going to buy aftermarket down pipe and really don't know the benefits besides sound according to this post response.
04-10-2014, 08:48 AM
#9
Senior Member
Join Date: 04-26-2009
Location: City of Champions
Posts: 666
Hate to bring this up from the past,but what I get from this is coring second cat on my factory downpipe,I get no engine light,and I'll pass emissions which is important for me,and no tune mods needed?thanks sorry kinda dumb.
Was going to buy aftermarket down pipe and really don't know the benefits besides sound according to this post response.
Was going to buy aftermarket down pipe and really don't know the benefits besides sound according to this post response.
No tune needed for this free-mod…
This mod helps low end torque…
04-10-2014, 09:10 AM
#10
Senior Member
Join Date: 04-26-2009
Location: City of Champions
Posts: 666
Any thin wall exhaust tubing will work fine…
I just clamped a 'vise-grip' wrench onto one end, & just used a firm, back-&-forth, side-to-side motion to 'cut' my way thru the 'cat'.
Takes maybe 10 minutes, to 'cut' thru the 'cat'…
The 'cat' core will be contained within this piece of tubing, after you
cut thru, so when you pull it out, no fuss, or muss…
No need to remove the DP, to do this free-mod…
Just disconnect the DP, at the back, where it bolts to the exhaust.
This really is a super easy free-mod to do…