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Been throwing a PO1400 on my '16 Z. This is for Cold Start Emission Reduction Control System. At cold start (temps under 110) the fuel mix is enriched (or maybe leaned) to quickly heat up frt. cats to improve emissions. Only runs for less than 30 sec. Was at dealer/service last week for 4 days. Have Mamo PTB/Borla X pipe w/frt. cats. Dealer didn't find problem & I didn't mention X pipe or TB cause I knew they would zero in on those & blame me. Service manual for this code mentions check air filter/PCV working properly/vacuum leaks past MAS/exhaust leaks. After getting car back (4 days) I jacked car & tightened exhaust bolts (rear were pretty loose/frt not really). Next am (cold start) lite back on. Cleared code, replaced OE TB, ran errands in town & again car sat overnite to cool. Oil/water has to be below 110 degrees for cold start to occur. 1st a.m. no lite, went to town running errands (some monitoring systems have to have so many drive cycles) not sure if 1400 does, before they reset & begin monitoring again. 2nd nite again sat overnite to cool, I used large fan running & blowing on engine both nites to be sure engine was cool in a.m. So, again no lite! 2 days in a row-Yeah. I'll give it 2 more days to be sure, but now appears it was definitely the TB. Probably allowing too much air flow(?) & couldn't get rich enough mix for this code. Really strange tho since TB had been on for 1 1/2 mos. It did appear more space between Mamo TB body & movable plate (?) & OE. He even states on his website, sometimes they are too aggressively ported & he will send a lesser ported TB if requested. I think I'll just "try" to get my money back but will understand if he balks. JUST SHARING info not really trying to hijack thread. Thanks
Last edited by madrob2020; 07-18-2017 at 02:03 PM.
A flow bench test is only going to tell you peak flow at WOT, most flow benches won't be able to generate enough of a pressure differential to measure flow at WOT to obtain any meaningful data on an orifice this size. We could however install them on three different vehicles and ask the drivers which one they like best.
Again, I apologize for getting off topic. Let's get back to what the OP asked. We can debate PTB and airflow dynamics in another thread.
C7gman,
Too may mods without a tune, your going to have to eliminate at least one. I would probably go back to a stock CAI and try just a filter like the BMS.
You need to use a better bench. I've measured the depression on a stock ZO6 with a digital manometer and it ramps up from 0 " at idle to 11" wot. That's peanuts for a good bench to control flow at various tb openings. Now, if all you are after is "feel"and drivability, then your test is valid. I'm after power and anytime I have reduced pressure drop in front of a sc , there is more power. I'm going to bench test the Mamo , stock and a few air filters soon to find the most flow. I would be surprised if the stock tb or Mamo goes over 850cfm at 11" of pressure drop. But the bench will tell.
Yes, GM techs confirmed to me last year at SEMA that the tune has "tightened up" on the 17s, they will pop the CEL much sooner then 15/16s, but under certain conditions, even the earlier models are vulnerable...
Definitely makes sense, thank you! I wonder if they also added some "security" steps that needs "cracking" to tune like the '17 camaros.
You may want to consider actually doing some research on airflow. Statements like "the hole isn't any bigger" clearly demonstrate that you don't have any idea on how airflow works beyond the layman understanding of "bigger is better."
Using your knowledge, everyone should purchase cylinder heads with the largest valves and port volumes available, a concept that was proven incorrect over 35 years ago when flow benches started to become more common in the automotive industry.
Flow benches allowed us to discover that a properly shaped small cross sectioned orifice could substantially outflow an improperly shaped larger orifice with the added benefit of increased throttle response.
I apologize if I sound harsh, but you have now posted your incorrect concept in multiple threads.
It's time to set the record straight.
The Katech PTB is a good product. IMHO the Mamo PTB throttle response and overall feel throughout the rpm range just happens to be better. I can make this statement because I own both and have swapped back and forth multiple times. I've also done blind taste tests with three friends. The results were unanimous.
You can't go wrong or be disappointed with either product.
The only way you can go wrong is subscribing to the "bigger hole is better" theory for anything on you car. There are more data points to consider.
Yes, I do know. Bigger is not always better and the thing that you did not mention where the hole (so to speak) is smaller or has less volume but outperforms a larger one is called 'velocity'. You can have 'volume' but you also need 'velocity'. You put those two things together correctly and you have a winning combination!
Personal Example of Size:
I ported a set of small 260cc Dart ovalport big block chevy heads. When I was done I took them to a local head/porting shop (that the owner has a longtime stellar reputation in the business) to have them flow tested; after testing he wanted me to work for him whenever I wanted. I read and talk to experts. I also know what a burr is.
Those oval port 260cc Dart heads flowed the equivalent of Dart's largest rectangular port 400cc heads at the time. You don't want to know how fast my 4,000 lb. 9.5 compression NA pump gas daily driven street/bracket car was.
PS: I have not tried both throttle bodies like you, but just let me say you are not the 'only' one on this forum that has tried both and that person had just the opposite opinion of your's. Remember one thing, CNC gets the same results 'everytime', something done by hand 'may' not.
Last edited by C7/Z06 Man; 07-18-2017 at 01:42 PM.
A flow bench test is only going to tell you peak flow at WOT, most flow benches won't be able to generate enough of a pressure differential to measure flow at WOT to obtain any meaningful data on an orifice this size. We could however install them on three different vehicles and ask the drivers which one they like best.
Again, I apologize for getting off topic. Let's get back to what the OP asked. We can debate PTB and airflow dynamics in another thread.
C7gman,
Too may mods without a tune, your going to have to eliminate at least one. I would probably go back to a stock CAI and try just a filter like the BMS.
You need to use a better bench. I've measured the depression on a stock ZO6 with a digital manometer and it ramps up from 0 " at idle to 11" wot. That's peanuts for a good bench to control flow at various tb openings. Now, if all you are after is "feel"and drivability, then your test is valid. I'm after power and anytime I have reduced pressure drop in front of a sc , there is more power. I'm going to bench test the Mamo , stock and a few air filters soon to find the most flow. I would be surprised if the stock tb or Mamo goes over 850cfm at 11" of pressure drop. But the bench will tell.
Currently Superflow 1020. Started with a SF300 in 1982.
You fail to mention the units. I can only assume you mean 11" of H2O at WOT on the car.
Lots of people made the same mistake flow testing cylinder heads at 10" of H2O because their benches weren't big enough. Those of us that could test at 28" and above learned a whole lot more.
Originally Posted by C7/Z06 Man
Yes, I do know. Bigger is not always better and the thing that you did not mention where the hole (so to speak) is smaller or has less volume but outperforms a larger one is called 'velocity'. You can have 'volume' but you also need 'velocity'. You put those two things together correctly and you have a winning combination!
Personal Example of Size:
I ported a set of small 260cc Dart ovalport big block chevy heads. When I was done I took them to a local head/porting shop (that the owner has a longtime stellar reputation in the business) to have them flow tested; after testing he wanted me to work for him whenever I wanted. I read and talk to experts. I also know what a burr is.
Those oval port 260cc Dart heads flowed the equivalent of Dart's largest rectangular port 400cc heads at the time. You don't want to know how fast my 4,000 lb. 9.5 compression NA pump gas daily driven street/bracket car was.
PS:I have not tried both throttle bodies like you, but just let me say you are not the 'only' one on this forum that has tried both and that person had just the opposite opinion of your's. Remember one thing, CNC gets the same results 'everytime', something done by hand 'may' not.
Agreed, everybody is entitled to their opinion, no argument for me there.
CNC's are not magic, they are great for duplicating a given design. That design can be good to start out with, better or best. Bad setups, dull tools will greatly effect the finished product. How do I know? Started running CNC machines in 1982. Programming simultaneous 5 axis in 1994.
Originally Posted by EMINENT 1
Do you have any other mods like xpipe or intake?
I did all my testing with just the throttle bodies in order to isolate the one change. But currently I also have an Xpipe, an intake and a tune.
Sorry all, I'm way off topic again. Lets get back to the OPs original problems.
Last edited by Rookieracer; 07-18-2017 at 06:11 PM.
Exactly, without the code no one here or anywhere else has a clue of what and why it happened.
Most of the codes (PO 106 for example) in other threads associated with this kind of event didn't reset themselves. So you could have had an event totally unrelated to all the recent buzz on this forum.
Probably not the case but without the code we simply don't know.
What cfm did the Superflow 1020 measure when you tested the throttle bodies?
I hope you were kidding about 11" of Hg!!!!! 11" of Mercury would collapse a CAI.......actually a lot less than 11". Manometers, depression, watergage , etc in the USA performance market are associated with inches of water....
Started on the manuals, moved into CNC operating and then CAD/CAM engineering and programming.
Good man.
My sons new hobby is messing with the 3D stuff, constructed his own printer from parts. Writes his own programs to make stuff for around the homestead, replacing/improving broken parts, etc.= Thinking about building a house using the tech which is not new i.e. building houses with it.
Last edited by C7/Z06 Man; 07-18-2017 at 06:34 PM.
What cfm did the Superflow 1020 measure when you tested the throttle bodies?
I hope you were kidding about 11" of Hg!!!!! 11" of Mercury would collapse a CAI.......actually a lot less than 11". Manometers, depression, watergage , etc in the USA performance market are associated with inches of water....
Agreed, which is why I asked. I also edited my previous post.
To be clear, were you testing between the CAI and the TB or between the TB and the blower?
I never tested the C7 TB on the bench, based on the area of the throttle body I didn't feel I could ever get them to 28" H2O, so why bother?
Have you tested the C7 TBs? How much pressure drop did you get?
Perhaps if I get motivated I'll machine a fixture and an entrance to see what I can get.
We're killing the op thread so a couple of observations:
1. Cylinder head development depression vs manifold inlet development depression is two different worlds via resolution. 40-56" h20 is helpful for head ports due to sonic flow, etc. 11" and lower for inlet design is more than sufficient since those components should never exceed that amount unless they are horribly designed and should be replaced.
2. I'm testing before and after for a future thread.
Here are the pics of the freeze frame data off of the code reader I used. I know you guys know a lot more about what some of this stuff means. I can figure out some of the things, guess on others, and no clue on some.
No Worries on the porting and testing info. This is good stuff to learn a little about too!
So the code is in: P0106 $07E8 Generic ManifoldAbsolute Pressure/Barometric Pressure Circuit Range/Performance
I will post the freeze frame data via pics later tonight.
Thanks again everyone!!!
That was the Vegas bet. The MAF is reporting less load than the MAP is expecting. Very common in 2017's. Can happen in other years with inlet airflow mods that fool the MAF. Best fix is to tune the MAF curve. 2nd best is turn off the code with HPT. Third best is remove an inlet mod and it might be enough to get back into stock range.
That was the Vegas bet. The MAF is reporting less load than the MAP is expecting. Very common in 2017's. Can happen in other years with inlet airflow mods that fool the MAF. Best fix is to tune the MAF curve. 2nd best is turn off the code with HPT. Third best is remove an inlet mod and it might be enough to get back into stock range.
Switched from the Blue Oiled Filter to the Grey Non-Oiled Filter tonight. As another member mentioned earlier, it seemed to help solve his issue.
We shall see......Thanks for the input!!!!
That was the Vegas bet. The MAF is reporting less load than the MAP is expecting. Very common in 2017's. Can happen in other years with inlet airflow mods that fool the MAF. Best fix is to tune the MAF curve. 2nd best is turn off the code with HPT. Third best is remove an inlet mod and it might be enough to get back into stock range.
Could be your theory is correct.
However I did notice 2 things that we haven't seen before.
1. This is the first time the MAP reading has shown the correct correlation to 9lbs or so of boost. (25 psi). So at least we know the MAP is reading correctly. Which confirms what many have said but we haven't seen until now.
2. The Long term fuel trims are fairly high on the positive side (+12.5%) and likely climbing (on the way to setting a P0171). This indicates an air leak or excess air in the manifold as compared to what the MAF sensor is seeing. This can be caused by MODs as you suggest.
However I have also seen this caused by some portion of the intake track after the MAF collapsing under heavy boost or suction and allowing unmetered air into the manifold. This condition is a bear to find because after the car is shut down or even at idle the gap caused by the suction re-forms to its original shape and is nearly impossible to discover.
I have been down this road twice over the years and it took a month to resolve in each case. Both times where shortly after I installed an after market intake. First time it was a loose clamp on the throttle body. 2nd time it was a clamp that was to tight on the plastic CAI housing that caused the plastic CAI housing to deform under suction and create a gap.
I say this not to contend with anyone diagnosis, but to say this could be the reason why some cars with and without MODs are experiencing this issue AND other cars configured exactly the same do not. With the fuel trims going high as indicated here there is definitely a vacuum leak somewhere. Others with the same or similar MODs aren't operating anywhere near 12% LTFTs.
Last edited by dar02081961; 07-19-2017 at 12:32 PM.
However I did notice 2 things that we haven't seen before.
1. This is the first time the MAP reading has shown the correct correlation to 9lbs or so of boost. (25 psi). So at least we know the MAP is reading correctly. Which confirms what many have said but we haven't seen until now.
2. The Long term fuel trims are fairly high on the positive side (+12.5%) and likely climbing (on the way to setting a P0171). This indicates an air leak or excess air in the manifold as compared to what the MAF sensor is seeing. This can be caused by MODs as you suggest.
However I have also seen this caused by some portion of the intake track after the MAF collapsing under heavy boost or suction and allowing unmetered air into the manifold. This condition is a bear to find because after the car is shut down or even at idle the gap caused by the suction re-forms to its original shape and is nearly impossible to discover.
I have been down this road twice over the years and it took a month to resolve in each case. Both times where shortly after I installed an after market intake. First time it was a loose clamp on the throttle body. 2nd time it was a clamp that was to tight on the plastic CAI housing that caused the plastic CAI housing to deform under suction and create a gap.
I say this not to contend with anyone diagnosis, but to say this could be the reason why some cars with and without MODs are experiencing this issue AND other cars configured exactly the same do not. With the fuel trims going high as indicated here there is definitely a vacuum leak somewhere. Others with the same or similar MODs aren't operating anywhere near 12% LTFTs.
Agreed.
Air leak is a quick po106. After a couple of mods I saw 4-5% plus LTrims and decided to fix the MAF curve and brought it back down to -2ish.
07-18-2017, 11:47 AM
