I failed my NYS Emissions test today. I don't know what it could be. The only engine mods I have are Stillen Y-Pipe, and JWT Intake. The car was decently warm. It sat for about 10 min only. But the guy doing the test did get heavy footed for a second and caused my car to growl a bit. I don't know if that made the difference. I was also running almost go gas with Cheveron Techron in it. Fresh engine oil. Just changed. Mobil 1. My car only has 35,000 miles on it. Here are my results.. I missed it by sooo soo soo little!! Results are as follows.

My Reading / Limit
HC: 0.52/0.80
CO: 5.43/15.00
NOx: 2.02/2.00 <--- Failed because of this!!

I told the mechanic guy there that I did have a Y-pipe. He said that the missing precats shouldn't affect the NOx levels. I don't know if this is true or not. He said that my EGR may be malfunctioning. Whats an EGR? Anyone else have this problem? This test was performed at a Sunoco gas station where I got my last alignment. I went there to ask the guy some questions about my alignment and got the inspection on there too. I'm thinking of just taking my car to my regular mechanic and having him run the test and seeing if he can get me to pass.. Otherwise. I'll have to pay someone 50 dollars and get passed illegally. Any input on this would be great. What causes high NOx?

ZuM

 

Do you have a cat? This might also big a shot in the dark but has the PCV valve been replaced?

 

Yep, I have the stock cat. I still have stock exhaust too. PCV valve? How often does that have to be replaced?

ZuM

 

Every 20-25k miles.

 

What does the valve do?? How much does it cost? I know its by the throttle body. But how hard is it to install? My friend has 50k on his 95SE and I don't remember him ever replacing that PCV valve.

ZuM

 

The PCV valve should be replaced. This is how it works. In the engine abviously it burns gas/air, for any unburned gas, it goes throught the PCV valve and recirculates back into the engine so it is more efficient. As far as installing it, it's kinda a pain b/c of its location, it may take a couple of mins to get out.

 

I just checked on Courtesy Parts and I only see a "EGR Valve". Not a PCV valve. That thing is pretty expensive! 80+ dollars. Is that what you were talking about?

ZuM

 

they are $3. for a pcv. i believe the y-pipe is your car's culphrit. not hating man but it affects emissions to get extra hp, right? no more pre-cats.

 

The guy at the testing place said it wasn't the cats. The precats only come into play when the car is cold. But once the main cat is warm all should be well. As my other #s indicated. The guy said if it was my y-pipe I would have high CO #s. He says high NOx indicates emissions control equipment problems. But I don't have any engine lights on. I found the PCV valve on Courtesy's website. Its not listed. But when you do a search it does come up. Its $6.90 or something. I'm going to call them up and order the valve and while I'm at that, I'll talk to whoever picks up the phone about my emissions etc.

ZuM

 

much luck zum.

 

I have a 95 Max with Stillen Intake/Y-Pipe/RT cat/and stillen cat-back exaust,here are my results I got a few weeks back in R.I.,

Reading/Limit
HC PPM IDLE 151 : 220
HC PPM 2500 RPM 58:220
CO%IDLE .41 : 1.20
CO% 2500RPM .55 : 1.20

This is on a 95 Max with 89K miles on it.
Before the test I put a fresh change of amsoil and a new Nissan fuel filter and some gauranted to pass stuff.I think if you get the guaranted to pass stuff you should definately pass,but remember to read the directions on the bottle.

 

I'm going to get some Guaranteed to Pass stuff. I hope they have it at autozone or pepboys. If not I'll have to order it online. I'll probably end up replacing my PCV valve also. It wouldn't hurt. I hope its not that EGR thing that the mechanic was talking about. =P

Thanks guys

ZuM

 

HOLLLD UP.
one question..did u have chevron in the gas tank when they ran the car?
if yes you should just try filling up w/ some gas. you failed by VERY VERY little. so something small like having a injector cleaner in the tank may have failed you.
the NOx is normally a emission part..(O2 and etc.)
PCV should be changed just becasue it's so damn cheap.
the gurantee to pass is another tank additive. you have to run that and then run a tank or 2 of straight gas...so before you start pulling your hair out try running the car w/ straight gas w/o any additives. also did they run the car twice on the dyno just to make sure?
Dan

 

Get rid of the chevron stuff.....and go get some fresh gas. Should pass then. Also...do some hard driving right before the test. If it only sits for ten minutes then you can insure you keep the cat nice-n-hot Dump the chevron stuff so your just running on gas.

Mike S.

 

So you don't think the PCV valve is the issue? Yes, I had cheveron techron concentrate in the tank. It was less than a 1/4 tank left though. Probably like 4 gallons. Maybe 3. I'll fill the tank up with fresh gas later today. My emissions is up on the 11th. So I don't think I can go through 2 whole tanks of gas before then. And no, they didn't run it again to make sure. They said they would have to charge me again. I wasn't going to risk blowing 70 dollars in one day. Thats two pretty good dinners. I'm going to see if the Koeppel parts dept. is open today. Probably not. But if they are I will get the PCV today and replace it. You think driving the car is a bad idea now or is it okay..

ZuM

 

believe me..there's NO dealer parts open.
just keep driving the car. there shouldn't be a prob. go get some super at your fav gas station (u said sunoco..ultra 94?). then drive it back to the shop and run it again. if u want to change the PCV just to make sure, u can do that. relatively pretty cheap part but i don't think it's necessary. what u can try is clean out the existing valve. there should be a little bit of oil residue in there. get some brake cleaner and clean it out. that should hold u.
BTW 70 for 2 dinners? how u getting to dinner w/o a car?
where do u go get your inspections done anyway??
Dan

 

Damn, technicalities.. You're right.. No dinner without a car.. =P I'm trying to take off the PCV valve right now to inspect it. I can't get it out of the engine though! I got the tube off. But my back it hurting from leaving over the engine. Am I supposed to take the rubber off too? I got it about 1/4 of an inch out. I'm gonna grab a bite to eat before I try again. And you're right, no parts open. I was just hoping there would be. I got the last inspection (the one I failed) at a Sunoco in Ridgewood. Cypress Ave. I got there beause a buddy of mine lives right there. His garage is half a block away. So if I end up having to wait, we just go work on his car or go to his place. But all the other times I took the car to this mechanic off 37th ave and Northern Blvd. In the junkyards. He is a friend of my father's. So he takes care of me. But I never had an issue with my emissions before. Always passed with flying colors. Only difference this time is the Y-Pipe and the Techron. And maybe a busted PCV valve? You have no idea how much my back hurts right now!! =P Gonna eat and continue. Any suggestions?

ZuM

 

The PCV valve is out. Seems in good shape. Not gunked up at all. I can easily press the valve open and close. I'm cleaning it up and I'll just drive the car. Should be fine. I guess maybe the techron was the culprit. Good call Dan.. =) Agggh.. hope it goes in easier than it came out.. =P

ZuM

 

you gotta give me directions on how to get that PCV valve out one of these days. I have been meaning to change it but you know--most cars can go easily 100K on the original without changing it. And btw, the PCV is a pain in the buttocks to get out. I saw it on Jeff's 60K service site.

good luck on the emissions. =)

 

Its in a tough place to get to. I would recommend a needle nose pliar thats 6 inches or longer. The longer the better. I only had one that was about 5 inches or 4. And it really wasn't good enough. What I did was use the pliar to pull the clamp off the house. Used a flathead screwdriver to get the hose off the valve. I had to remove the bracket to the little circle thing near the throttle body. Its this silver dollar sized thing with tubes going into it. I removed to two bolts holding it down to get some more room. I also had to remove the bracket holding down the tube that goes into the PCV valve. All this was just get get some room to work. The bolts are 10mm bolts. After you get the hose off the top. It will just sit there in your way.. I didn't bother to work harder to make more room. I started prying at the valve OVER the rubber. Don't pry at the rubber. I just stuck a big flathead in there. Wedged it in then turned the screw driver. Then went to the back of the valve. Did the same thing. That should get it out about 1/4 inch or so. Then you just pry at the front. Then the back. Etc. It will eventually come out. Take your time. Don't drop the valve when you get it out. I almost did and I ended up holding the valve up with just my middle finger pinning it against a hose. Had to get my other hand in there to make sure I didn't drop it. Anyways, its pretty straight forward. Mine was pretty clean. I put a paper towel on the input side of the valve. And blew into it. The valve opened up fine and I felt the air come out the other side. But then again, I only have 35k on my car. The condition of the valve may depend on the gas you use and stuff like that. The valve is operated by a little rubber gasket holding a pin type plug. If there is enough pressure the rubber moves back with the pin and lets air out. So I guess if you had some really dirty gases. Maybe been using some cheap gas.. It could gunk up the rubber and or the pin.
Welp, I'm gonna run my current tank of Mobil 93 octane down. Then try for emissions again. =)

ZuM

 

OMG your still on that?!?!
i know i gave u more directions than you can shake a stick at. if you want i'll install it for u if your going to the MA meet. it takes me about 10 min.
sheesh..just undo the hose and yank it out.
Dan

 

Zum--thanks a lot for those directions--
best of luck on those emissions test--
let us know if it goes through!!

I think the engineers at Nissan did a great job of packing a lot of things in this tightly wounded space. As for the PCV, I was going to change it three weeks ago maybe, but there was rain and rain--you remember and it was darn cold too. So I wanted until this weekend. I had that little incident with the last spark plug as I was changing it--the fartest one in back bay area. Anyways, I had to prop myself up with a milk carton to see better (I am short alright!!) and darn it, when I pushed, I fell off the carton--more like the carton gave away under my feet and I fell and skinned my hands and after that, I had to remove the egr to get more space to get the socket in.

And I was poooff tired and hurt afterwards--yes, quite embarrassing. And sure, you can have the honor of changing it when I catch up with you It'd be an honor to finally meet all of you, guys. hehe

 

believe me....i've worked on worst.
try to change the plugs on a buick w/ a 3.8L which have about 2-3 inches of clearance. you can't even see the hole for the plug. then right behind it is a metal heat shield READ--CUT HANDS. then the middle one you have the O2 sensor in the way. to get the 3rd one you have to be on top of the engine (feet off the ground) and get to it.
how about the plugs on a Camaro IROC-Z..the 2 last plugs on that V8 is hidden. you have to get UNDER the car to get to them...and u can't even see them.
let me tell u...the max is a piece of cake to work on.
Dan

 

It's not the PCV valve system. If the PCV valve system was faulty, it'd cause the hydrocarbons to be high, not the oxides of nitrogen. The PCV system scavenges excesive crankcase vapors. Fresh intake air is mixed with the blow-by gas.. these are sent through the PCV valve into the intake manifold.

It's a piece of cake to replace on the Maxima engine compared to the Z32 engine.. which have two.. DOH... 2.5 hour job for both since there are vacuum hoses, brackets, etc.. to remove before the PCV valve is accessible.. plus, once it's accessible, it's a ***** to pull off the hoses and a pain to pull out the valve itself.

Here it is on the VG30DETT engine after the hoses/brackets are out of the way.:
<img src="http://www.cyberhosts.net/~gotrice/ecza/aug17_00/09.jpg">
<img src="http://www.cyberhosts.net/~gotrice/ecza/aug17_00/03.jpg">
Even easier when the engine is out..
<img src="http://www.cyberhosts.net/~gotrice/ecza/aug17_00/04.jpg">

I didn't read the whole thread, but it seems like your EGR valve is not recirculating burnt exhaust gases back into the combustion chamber. At around 1000 rpm to 3200 rpm, the EGR should be functional. By recirculating the burnt exhaust gas (inert), it takes up space within your combustion chamber, thus, reducing cylinder temperatures and pressures. NOx is generally produced @ 2000 deg F. By reducing the cylinder temp, the amount of NOx is drastically reduced.

The other possibility is a clogged main cat.

 

Phuong,

Wow, this just gets worse. I assume the EGR being emissions control equipment is covered under warranty. It wouldn't fail because of my intake or y-pipe right? You think my main cat may be damaged from this? I think I'll take it to my mechanic and have him drop my cat and check it out. If my cat is okay I'll take it to the dealer and have them fix the EGR. Hopefully they will fix it under warranty despite my Y-pipe. They won't have to put the car on a lift to do the EGR will they?? Maybe they won't even know the pipe is there. But if my cat is fried. I'll have to get a RT cat or something.. =) But its more money. I don't want to spend anymore on the car for now.

ZuM

 

see told u it wasn't the PCV.
i doubt its your cat. they last a while...well unless you have been running the engine really rich to clog it.
i say check the EGR.
and that pic of the PCV on the VG30DETT...HOLY $HIT!!! that looks like a PITA to do off the freggin car...i don't want to know what it look like while the engine is IN the car.
Dan

 

I was hoping it would be the PCV! =) You know, hoping its the little fix. Denial! Hehe I don't think my car is running that rich. Don't see black smoke or anything. Don't really smell the gas smell except on startup. When its warm the smell goes away. I think that initial smell is because of the missing precats. Or it can be denial talking again.. All my other emissions levels seem okay so doesn't that mean my cat is okay?
I've always heard that the VG30DETT wasn't a userfriendly engine. The turbos are on the bottom of the engine or something. But its still a sweet engine.. =)

ZuM

 

I think you need to replace your EGR (Exhaust Gas Recirculation)valve. It perfoms a task similar to the PCV valve but for different reasons. The EGR valve helps lower the peak combustion temp and reduces Nitrogen Oxide levels.

tmax