D16y7 smoking at 4,000 rpms

Stephen staly

New Member
So I have a 96 civic DX d16y7 with a spectra cone filter intake and a long tube 4-2-1 header no cat. I can rev it up and as soon as it hits 4,000 or higher white gray smoke comes out. Does anyone know what this could be? Is it bc there is no cat? Plugs indicate it is running mint not lean nor rich I could really use some help

Plugs
 
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HeX

Authoritah, respected.
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Have you inspected the spark plug cylinders for oil leaks?
 


MotorMo

Respected
Grey smoke normally indicates excessive Fuel being unburned and shooting out the tail pipe. This can leave black 'soot' on the muffler tip and bumper.
White smoke=coolant, or steam burning off,
Blue smoke is normally oil burning.
Strange tho because normally when we put on upgrades to allow our engines to breath in more air- they tend to run leaner with out a tune to accommodate the more air now flowing through it.
-"Slapping" the throttle to quickly race the engine up to 4,000 RPM's should poop out some extra fuel by design. But if your holding it at 4,000 RPM's steady with no load, black smoke probably shouldn't be happening. If thats the case I would be suspicious of a faulty primary O2 sensor.
With out a cat, you will see more smoke coming from your tail pipe- the cat normally would take this extra Hydro Carbon's (fuel , HC) and Carbon Monoxide (CO) and turn them H20 and CO2- which is smokeless and odorless.
 

Stephen staly

New Member
MotorMo said:
Grey smoke normally indicates excessive Fuel being unburned and shooting out the tail pipe. This can leave black 'soot' on the muffler tip and bumper.
White smoke=coolant, or steam burning off,
Blue smoke is normally oil burning.
Strange tho because normally when we put on upgrades to allow our engines to breath in more air- they tend to run leaner with out a tune to accommodate the more air now flowing through it.
-"Slapping" the throttle to quickly race the engine up to 4,000 RPM's should poop out some extra fuel by design. But if your holding it at 4,000 RPM's steady with no load, black smoke probably shouldn't be happening. If thats the case I would be suspicious of a faulty primary O2 sensor.
With out a cat, you will see more smoke coming from your tail pipe- the cat normally would take this extra Hydro Carbon's (fuel , HC) and Carbon Monoxide (CO) and turn them H20 and CO2- which is smokeless and odorless.
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Well thank you so much everyones help is well appreciated. I did have a leak in spark plug cylinder#4 so I rebuilt the valve cover and it seems better. Only thing is now when I take it down the road and it hits 4-5 thousand and it puffs out grey smoke and when I shift. So it seems to only do it at high rpm.
 


Stephen staly

New Member
MotorMo said:
Grey smoke normally indicates excessive Fuel being unburned and shooting out the tail pipe. This can leave black 'soot' on the muffler tip and bumper.
White smoke=coolant, or steam burning off,
Blue smoke is normally oil burning.
Strange tho because normally when we put on upgrades to allow our engines to breath in more air- they tend to run leaner with out a tune to accommodate the more air now flowing through it.
-"Slapping" the throttle to quickly race the engine up to 4,000 RPM's should poop out some extra fuel by design. But if your holding it at 4,000 RPM's steady with no load, black smoke probably shouldn't be happening. If thats the case I would be suspicious of a faulty primary O2 sensor.
With out a cat, you will see more smoke coming from your tail pipe- the cat normally would take this extra Hydro Carbon's (fuel , HC) and Carbon Monoxide (CO) and turn them H20 and CO2- which is smokeless and odorless.
Click to expand...
Can't really figure out how to post pictures or I would. This spark plugs are a creamy white color which as fast as I know indicate it is running fine. So it's bc I have no catalytic converter on it right? If so should I get one to stop this ? If so when running a long tube header do I get a stock one or a magna flow high flow and a new cat back for a ex?
 

MotorMo

Respected
A cat would only help the situation of the smoke coming from your tail pipe.
'Creamy white' sounds about right- with a factory ECU.
After market 'high flow cats' kinda suck and don't do alot- They do how ever make it look like you have a cat, so if a cop throws a mirror under your car (welcome to California) he will see something that resembles a cat. But there won't be alot of 'special metals' in the high flow cat to change your smoke into clean air.
I tuned my naturally aspirated, built B18C1 with and without a cat. It was on a California 'legal' aftermarket cat that had the inlet and out let diameters opened up to 2.5 inches. The difference was 1 horse power, I kid you not. So for me, I always use a cat unless I'm running a turbo or other boost. It also makes your car not smell like crap haha.

Do you get a puff of smoke out the back when you take off from a stop light that you have been stopped at for a while?
 

Stephen staly

New Member
MotorMo said:
A cat would only help the situation of the smoke coming from your tail pipe.
'Creamy white' sounds about right- with a factory ECU.
After market 'high flow cats' kinda suck and don't do alot- They do how ever make it look like you have a cat, so if a cop throws a mirror under your car (welcome to California) he will see something that resembles a cat. But there won't be alot of 'special metals' in the high flow cat to change your smoke into clean air.
I tuned my naturally aspirated, built B18C1 with and without a cat. It was on a California 'legal' aftermarket cat that had the inlet and out let diameters opened up to 2.5 inches. The difference was 1 horse power, I kid you not. So for me, I always use a cat unless I'm running a turbo or other boost. It also makes your car not smell like crap haha.

Do you get a puff of smoke out the back when you take off from a stop light that you have been stopped at for a while?
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Nope only at high rpms that I noticed. You think I need a tune? If so would a hand held jet brand work from jegs? I called and was thinking about trying that. And they found one that would plug into my car for 359$
 

MotorMo

Respected
A good tune will compliment the mods you've done- but true good tuners are very hard to come by. A bad tune can do more harm than good.
My vote: I think if your running with stock internals you should get a cat, and that there are no "over the counter" tunes that are worth buying.
--"Nope only at high rpms that I noticed."-- Just checking on your valve guide seals :thumbup: Ruling them out.
 

Stephen staly

New Member
MotorMo said:
A good tune will compliment the mods you've done- but true good tuners are very hard to come by. A bad tune can do more harm than good.
My vote: I think if your running with stock internals you should get a cat, and that there are no "over the counter" tunes that are worth buying.
--"Nope only at high rpms that I noticed."-- Just checking on your valve guide seals :thumbup: Ruling them out.
Click to expand...
So I should get a regular or like a high flow cat? Also what do you think I should do next as far as my build goes
 

MotorMo

Respected
"After market 'high flow cats' kinda suck and don't do alot-"--- I would recommend a regular cat converter. You could also have a muffler shop open the inlet and outlet of the cat to match the size of your header outlet and your b pipe inlet for best flow.
A build is a personal and intimate path. Its hard for me to tell you what you should do next. There are many options- Swapping your Y7 intake manifold for a Y8 would help your engine to breathe better- and swapping out your Dx tranny for an Ex tranny with better gear ratio's would make the car 'feel' faster.
 

Stephen staly

New Member
MotorMo said:
"After market 'high flow cats' kinda suck and don't do alot-"--- I would recommend a regular cat converter. You could also have a muffler shop open the inlet and outlet of the cat to match the size of your header outlet and your b pipe inlet for best flow.
A build is a personal and intimate path. Its hard for me to tell you what you should do next. There are many options- Swapping your Y7 intake manifold for a Y8 would help your engine to breathe better- and swapping out your Dx tranny for an Ex tranny with better gear ratio's would make the car 'feel' faster.
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Okay I'll look into the cat. But I want to do the y8 Im swap and also I heard the d16z6 tranny is the best swap bc they have the shortest gears. Could I put a 95 tranny on my 96 and still pass ny emitions. Or would it not fit and throw a code. Also I wanted to do a stage two clutch and a light weight flywheel. If need be I could look into the 96 ex swap
 

Krukowskid

New Member
You can use any D hydro tranny (92-00) with your d-series. In Europe shortest tranny is from EG3 noblesse 4.4FD + 1st, and 2nd Gear from dohc CRX. Transmission would not change your emission.

About smoke, do you recognize any Oil/coolant loss, if Yes How much for 1k Miles? Is it same situation when you are rev slowly?
 
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Stephen staly

New Member
Krukowskid said:
You can use any D hydro tranny (92-00) with your d-series. In Europe shortest tranny is from EG3 noblesse 4.4FD + 1st, and 2nd Gear from dohc CRX. Transmission would not change your emission.

About smoke, do you recognize any Oil/coolant loss, if Yes How much for 1k Miles? Is it same situation when you are rev slowly?
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Idk but it's only when you stop it. Like I start rolling and as the rpms pick up put it down more and more and mash it at 3 thousand and when I hit 4-7 it smokes and then shift and it poofs out smoke and then goes away by the looks of it at lower rpms.
 

Stephen staly

New Member
Krukowskid said:
You can use any D hydro tranny (92-00) with your d-series. In Europe shortest tranny is from EG3 noblesse 4.4FD + 1st, and 2nd Gear from dohc CRX. Transmission would not change your emission.

About smoke, do you recognize any Oil/coolant loss, if Yes How much for 1k Miles? Is it same situation when you are rev slowly?
Click to expand...
Stomp *
 
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