SHADY280

dont forget, my early 79 model doesnt have a o2 sensor so thats why on well tuned car it may have adverse effects.

RodMoyes

^ Yup...

1980 has no o2 sensor either...

I may not know EVERYTHING, but after 18 years in the business, and half of that as a store owner... I know a little thing here and there.

I have seen first hand the difference a functioning EGR has on a car with no other means to compensate for it's loss.

It may not be HUGE, but it DOES matter.

Rod.

P.S.

To those who want to remove/cap it off anyway...

Your car=Your deal.
No one said you had to take my advice.

jfairladyz

Like I said, without an o2 sensor the car can't compensate. But if you've got an o2 sensor then the ECU will simply correct the slight difference in mixture ratio. And I've seen that firsthand. I do believe the original question was directed toward a 280zx Turbo which does indeed have an O2 sensor. When the car is cold it doesn't use the EGR valve. When it warms up it starts using the o2 sensor. So the ECU will never even know the EGR isn't even there. On the turbo cars though I would leave the EGR control plugged into the ECU so it doesn't cause any issues there. The NA cars dont have that electronic control and instead rely on a TVV to control the EGR. That can just be capped.

The EGR only operates at part throttle. It's not meant to operate at Idle or WOT. If it were operating at idle it would cause rough idle/stalling issues. If it operates at WOT then it's robbing power. At part throttle the ECU is relying on the O2 for its mixture. EGR or no EGR, if you've got an o2 sensor then the ECU is compensating for it. The original poster does indeed have an O2 sensor. And if the o2 sensor is bad then the ECU will automatically revert back to warm up mode after about 20-30 seconds of getting a bad signal from the O2 after warm up. So the car goes rich anyways.

NismoPick

On a side note... all the people using the N42 intake obviously don't have an egr... as there isn't a spot for it on the manifold. YAY!

Hum... does that mean the N42 setups didn't have an O2 sensor?

SHADY280

nope and neither did my n47. they were both pre 80. and the computers were less sophisticated. the n47 had egr, but no o2

zmanofwashingto

Other than for visual inspections on emissions tests, these cars will run fine without an egr. In Cal they have the visual insp. so you can block it off with a plate and then put it back on when your trip to the smog ****'s comes around. Deleting the egr won't have any negative reactions in the running of these cars, or on the first gen ones either. The 80 Cal cars didn't even come with an egr, but the federal ones did. If you're smog exempt, and you want to clean up the engine compartment you can either get an 80 Cali manifold, or you can hack off the egr section and just have it heli-arced shut. Then take your egr tube on the exh manifold, hack it off at the top of the nut (exhaust manifold end) and weld it shut. Cleans things up real nice. For the Wash. state cars 81 and older they're exempt, and we only need a visual inspection if we're applying for a waiver. An egr valve won't affect any emissions test adversly or have any negative running effects if it is removed or blocked off. I've been doing it for years on many z's.
By the way, blocking off the POV can be very harmful to your engine, and you're much better off using an adjustable POV in it's place. I cringe every time I see a plug in the place of the POV. All it takes is one big enough backfire through the intake and it can blow your turbo, and can possibly split your intake manifold, or damage a piston, or split your intake tube from the turbo. I know that some of you are bound to say that you've been running it that way for years without a problem, but all it takes is one time to rip your engine a new one. Is it really worth it? I've got a car in here right now that the owner didn't listen to me and had an intake sneeze, lost all power, and the engine started smoking within about a quarter mile. We'll be pulling his turbo next week to replace it, I doubt if the turbine wheel is salvageable which means the cost goes up considerably. Consider yourselves forewarned of impending doom.
Z man of Washington
www.zspecialties.com

SHADY280

the hardest part ive found is the plug for the exhaust manifold side, if anybody wants to know its 22m by 1.5 thread count. the intake side is 3/8 npt. go figure

NismoPick

Sounds like he didn't have a BOV either....

Jeff must be stupid too ( http://www.angelfire.com/extreme/280zxt/ )

and anyone that's using the N42 intake on their turbo setup.

jfairladyz

If you've got a BOV then you dont NEED a POV. It's meant to protect the manifold anyways, not the turbo. It's located on the manifold. The throttle plate is blocking any pressure from getting back to the turbo anyways. It's only purpose to prevent over boosting in the manifold. It's not meant to protect the turbo. I'd still recommend keeping the POV for safety reasons, but I see no harm in removing it if you've got a BOV. (feels weird putting it that way since they are basically the same thing)

And the EGR DOES have an effect on emissions output. I dont know about the other 49 states but in CA they test for NOx. The EGR lowers the combustion temps which in turns reduces NOx levels. If it didn't have any effect on emissions then why, oh why, would the manufacturers have put them on? Obviously they tried to work around it with the non EGR cars. But judging by the fact that they reverted back to the EGR system (as did all other manufacturers) that says that the EGR must indeed have an impact on emissions.

WildmaN

Yes the EGR lowers the NOX levels here in AZ. I know, because that is the only thing I passed all 3 times, I have been to emissions. And only because I cleaned it real good. And made sure it worked, before I went any further. And it shows, with my emissions readings.

nismo619

well in a statement located way back the egr affects the oxygens sensor.. my problem i found out that the oxygen sensor has had a defect from the factory? am i right ? thats why i disconnected it the green wire i do belve underneath the passenger side floor board... i read a post a looooong time ago saying the top left sensor would come on only turbo z cars after they were first run somthing like 35,000 miles... yea when i do connect the wire back up the sensor light still comes on.. even thou i bought 2 breand new oxygen sensors... anyways ill be delteing the egr valve to clean up my engine bay kinda kie nismo did but im gonna hand poilish me a plate.. =-) i will keep yall informed of my progress...

NismoPick

There is no "defect" with the O2 sensor... Nissan wanted the O2 sensor to be changed @ ~35k miles, so they put in the sensor warning light, and the Nissan tech was to disconnect that GREEN wire when they service (replace) the O2 sensor. That turns off the sensor light on the dash..... again: it's not a defect, it was designed to work that way.

nismo619

I understand that nismopick.. should i hook back up the green wire ? but the sensor light still comes on... ? what do u think ?

jfairladyz

You don't hook that wire back up. It wasn't designed to ever be hooked up again. I dont know why Nissan designed it that way, but they did. Just leave it disconnected. It's almost like they didn't intend these cars to last 70,000 miles. On newer cars the light is simply reset at the ECU and will come back on when the time comes around again.

But yeah, dont mess with those wires. Those are in no way linked to the actual O2 sensor and have nothing to do with it's circuitry.

lifegrddude

I think he's getting at keeping the wire unplugged man. It serves no purpose other than to light up after 35000 miles. Nothing to do with actual O2 sensor function.

lifegrddude

Lol J, you beat me to it. I gotta type faster haha.

nismo619

Up date since i dont use the air cond... i delted it today the holy damn thing.. umm now i have room to work.. tomorow i will be taking off the exhaust manafold and intake manafold.. why am i doing this? u might ask well i just want to make sure all my gaskets are tight and not worn out... i will keep yall informed of more stuff ... should i clean out the intake manadolfd and if so with what ? carb cleaner ? should i try an bore out the holes ? any sujuestions would be very helpful.. thanks , ken

NismoPick

Clean them... yes... use DEGREASER. "Purple Power" from AutoZone works great.

Boring... I would suggest NOT to, unless you have spares, or previous experience.