Failed emissions.. Please Help

[thebutcher37]

Hey peeps, I need help.

if you look on my included picture its of my test results if you look to the farthest right   [NO (PPM)] is why i failed the Max is 815, and mine was 835.


IF possible please inform me of what i would need to get it to pass.

So the car is a 1991 318is coupe... DUH!

It has 241,347 miles Ive been using 91 octane since i got it Easter Sunday of 2008, within 3 months of purchase my tune up included, K&N drop in panel air filter, new spark plugs, fuel filter, Lubro Moly brand valve clean and jectron fuel system cleaner,and switching to Mobil 1 full synthetic oil and maintaining a 3k mile increment oil changes. so Ive been told it could possibly be the aftermarket headers that are on the car, would anyone else care to chime in on what i should do in order to pass? I would appreciate it Thanks.

[bmwconnect]

hehe I could write you chip to pass but it would be a experimental idea and nothing I offer officially .
PM me if you are interested

[DesktopDave]

Check for a vacuum leak, bad throttle position sensor or sticky idle control valve.  They can all make the car run a bit lean...that makes for low HC & CO with high NOx like your readings show.  We don't have knock sensors, so it can't be that.

I'd also think about changing the O2 sensor.  If you don't know how old it is, I'd replace it as part of the tuneup.  A late model Ford sensor can be spliced in to save you the $120 or so that an OEM one costs.

[bmwconnect]

Check for a vacuum leak, bad throttle position sensor or sticky idle control valve.  They can all make the car run a bit lean...that makes for low HC & CO with high NOx like your readings show.  We don't have knock sensors, so it can't be that.

I'd also think about changing the O2 sensor.  If you don't know how old it is, I'd replace it as part of the tuneup.  A late model Ford sensor can be spliced in to save you the $120 or so that an OEM one costs.

+1 for all those great ideas. A lot of times it is a slow 02 sensor with no life left

Good Luck!

[thebutcher37]

Check for a vacuum leak, bad throttle position sensor or sticky idle control valve.  They can all make the car run a bit lean...that makes for low HC & CO with high NOx like your readings show.  We don't have knock sensors, so it can't be that.

I'd also think about changing the O2 sensor.  If you don't know how old it is, I'd replace it as part of the tuneup.  A late model Ford sensor can be spliced in to save you the $120 or so that an OEM one costs.

no vacuum leaks, ill have to check for the TPS (throttle postion sensor), but i just replaced my crappy idling ICV (idle control valve),

More info on the o2 sensor i've heard but not sure what exact o2 sensor to get and reading some threads just got me more confused cause people be saying its a good idea and some say its not, and people have different o2 sensors... any one agree on one yet?

BTW thanks for the quick responses

[4banger]

i doubt the header makes a difference. my brother lives in maryland where they have emmisons testing and his 318is has one of my custom headers on it with a custom exhaust and it passed emmisons. it actualy tested 2 points lower with the exhaust and mustang injectiors than his stock 91 4door. id look to the stuff dave pointed out.

[DesktopDave]

Did you do the coolant heater & hose delete mod?  Since you're failing  the sniffer that might be enough to get a pass and it's worthwhile anyway.

If you're sure you have no vac leaks, might be a bad AFM, intake manifold gaskets, or even a stuck injector/bad wire/bad coil.

I know I'm going to catch some flack for an oil opinion, but if you're running synthetic oil I'd go for a longer oil change interval, like 7500 miles or the OEM schedule.  Just my opinion, doesn't hurt to change it more often.

[thebutcher37]

Check for a vacuum leak, bad throttle position sensor or sticky idle control valve.  They can all make the car run a bit lean...that makes for low HC & CO with high NOx like your readings show.  We don't have knock sensors, so it can't be that.

I'd also think about changing the O2 sensor.  If you don't know how old it is, I'd replace it as part of the tuneup.  A late model Ford sensor can be spliced in to save you the $120 or so that an OEM one costs.

OK when i go into autozone what do i ask for? I almost was going to go in asking for a 2002 4.6l mustang o2 sensor, but i realized thats wrong, so should I go in asking for the 1994 one? which model/engine?

i doubt the header makes a difference. my brother lives in maryland where they have emmisons testing and his 318is has one of my custom headers on it with a custom exhaust and it passed emmisons. it actualy tested 2 points lower with the exhaust and mustang injectiors than his stock 91 4door. id look to the stuff dave pointed out.

Since I suck in reading threads would you do me a big favor and post in here or a PM and let me know which mustang injectors I should be using, I.E. Whats year model/engine... I have read a couple threads and it never fails for me to want to do what the OP posts but then i read some contradicting comments later on in the thread from other board members and im just like NM i dont want to risk it.

Did you do the coolant heater & hose delete mod?  Since you're failing  the sniffer that might be enough to get a pass and it's worthwhile anyway.

If you're sure you have no vac leaks, might be a bad AFM, intake manifold gaskets, or even a stuck injector/bad wire/bad coil.

I know I'm going to catch some flack for an oil opinion, but if you're running synthetic oil I'd go for a longer oil change interval, like 7500 miles or the OEM schedule.  Just my opinion, doesn't hurt to change it more often.

I have a lot to learn, I dont know what the Coolant Heater & Hose Delete Mod is?  I did a quick search and didnt come up with much besides "the mess of hoses under the intake" and some other How to's that didnt seem to mention "coolant heater & hose delete mod".

It is possible I have sticking injectors , Just last night I drove the car since earlier in the morning, and at around 4k-5k RPM in all gears i had hesitation. But this just seemed to happen during the car warming up aftr a few miles/minutes I didnt notice it again. Ill also check out my spark plugs.... Im gonna check up on what you mentioned about the AFM and Gaskets if possible and ill think about longer oil change..

Thanks for all your help so far.

[4banger]

shit dave i change my oil every 12k miles wether it needs it or not lol

the injectors i used in his car were from a 90's 302(5.0) out of a fullsize bronco.

[thebutcher37]

I updated this thread earlier today but i guess it didn't get submitted.... Heres the jist of what i had wrote:

I spent the day at the local junk yards trying to get a set of headers, and miscellaneous crap for my car as well as my brothers. Came up empty on the headers but got scraps for my sunroof...

But I checked my spark plugs and the diagnoses is I have oil on the 2 spark plugs closest to the front of the car, with the one closest to the front being the more soaked. I guess this would be the cause of my hesitation/loss of power while driving the past few days or so, and hopefully why I didn't pass smog. Along with that I've been told i need a new profile gasket kit (if thats what its called) because of the oil... So one more thing to add to the list.

Lastly I'm unsure about what o2 sensor to buy. I dont want to spend $150 for an oem one, even autozone's Bosch OEM #13109 is $115, and they also have a bosch universal #15736 for $105, Im thinking I will try a member ///m42's method which has been working for him. I checked for a 2002 Mustang GT 4.6L o2 sensor #15716 $43.99 @ Autozone (I literally held it in my hand to make sure it has 4 wires 1-Grey, 1-Black, 2-white)

So a new update will come on monday, I hope to:
1. New spark plugs (suggestions? Autozone says Champion coppers $1.99ea)
I currently have Bosch Super+Plus FR7LDC, should I stay?
2. New o2 sensor
3. New profile Gasket kit
4. Pass smog

[DesktopDave]

But I checked my spark plugs and the diagnoses is I have oil on the 2 spark plugs closest to the front of the car, with the one closest to the front being the more soaked. I guess this would be the cause of my hesitation/loss of power while driving the past few days or so, and hopefully why I didn't pass smog. Along with that I've been told i need a new profile gasket kit (if thats what its called) because of the oil... So one more thing to add to the list.

So a new update will come on monday, I hope to:
1. New spark plugs (suggestions? Autozone says Champion coppers $1.99ea)
I currently have Bosch Super+Plus FR7LDC, should I stay?
2. New o2 sensor
3. New profile Gasket kit
4. Pass smog

I'd start with the cheap & easy stuff.  Usually it's the stupid things that cause trouble in my experience.  Mostly that means it's me.    

First, the free stuff:
You should always start with the "stomp test" to pull trouble codes from the engine.  Get  a pen & paper, then turn the key to the second spot (where it is  when the car is running) but don't start the engine.  Then quickly stomp  the gas pedal 5-6 times.  If you do it right, the check engine light  will start blinking.  They'll repeat until you turn the ignition off, so  don't panic if they start before you're ready to start counting.  If  you don't see any blinking and your CEL isn't burned out, just repeat  the process until it works.  The codes are listed on a great  page here.   I bet you'll see a 1215 or 1222.  You're looking for a 1444 if the car thinks  everything is kosher.

Next I'd go get my trusty multimeter & test all plug wires and coils.  My car is cold-blooded too, she hesitates & bucks for a few miles until she's warmed up.

Next, the cheap stuff:
I'd definitely get some new plugs in there, a new O2 sensor, and maybe do the cam cover gaskets too.  I think we all get oil on the plugs though...it's a common problem with these cars.  I haven't had much luck with the Champion plugs...I'd go for NGK coppers.  They're cheap & have solved problems for me on several cars in the past.  I've also used Denso Iridiums, they're really overpriced but they last a long time.  Bosch makes nice plugs too, but IDK if platinums or +4s are worth what they cost.  Opinions welcome for plug choices...

The new O2 sensor is a great idea.  I thought all the modern Ford V8s used the same sensor?  I'm not sure about that.  My cross-ref came up with a Ford Econoline V8, how much different could any other Ford modular V8 be? :confused:

I'd hold off on the injectors and the hose delete mod (it's removing the rat's nest of stuff under the intake manifold) until the car is legal.

[thebutcher37]

Next, the cheap stuff:
I'd definitely get some new plugs in there, a new O2 sensor, and maybe do the cam cover gaskets too.  I think we all get oil on the plugs though...it's a common problem with these cars.  I haven't had much luck with the Champion plugs...I'd go for NGK coppers.  They're cheap & have solved problems for me on several cars in the past.  I've also used Denso Iridiums, they're really overpriced but they last a long time.  Bosch makes nice plugs too, but IDK if platinums or +4s are worth what they cost.  Opinions welcome for plug choices...

The new O2 sensor is a great idea.  I thought all the modern Ford V8s used the same sensor?  I'm not sure about that.  My cross-ref came up with a Ford Econoline V8, how much different could any other Ford modular V8 be? :confused:

I'd hold off on the injectors and the hose delete mod (it's removing the rat's nest of stuff under the intake manifold) until the car is legal.

Okay I will do the multimeter and stomp test when i get home.

For now I have the cam cover gasket set, spark plugs and o2 sensor...

what gasket sealer do i need for the cam cover gasket? Red silicone, Grey silicone...

Off to put them on, ill check back for which sealant to use.

[DesktopDave]

I don't use any sealer until the gaskets leak.

[PumpItUp]

some people believe synthetic oil ruins your cat. (go ahead and crucify me for bringing this theory up :rolleyes:) i have some friends and they've become almost convinced on this.. after years of struggling with the california smog to pass their old japanese cars. is it plausible?

personally I never got the point of synthetic in old cars. i tried it once on my 318is (100,000miles) when mobil 1 was on sale and it smelled like shit out of the exhaust, especially at start up. it didn't do that when i switched back to 10-40 penzoil or whatever is in there right now (don't actually remember). i'm not anal about this like some people. but i am pretty strict about changing it every ~2500 miles. so it makes sense economically to not use synthetic. i don't care if synthetic gives you 1-2hp, i'm more worried about my oil not burning.


as for your immediate fix.. i think we all failed that nox ppm section. and yours is just barely. a new profile gasket is great and all but save that for after you've passed. for the re-test just take it there in the warmest part of the day honestly it will make a bigger difference

[flyinglizard]

If you are using synthetic. Maybe a change to 20/50 dyno would get you out.Also, check the cam timing, retard the intake a tiny bit. .  Make sure that the plug gap is  as wide as it will run with.  Try it again.  If still very close, add some card board in front of the rad to get it well up to temp. maybe drop off the engine fan, add some  drygas (I qt,) to the fuel. As a last chance, remove the cover of the airflow meter and raise the spring pressure 2 clicks. make sure that you mark it well before you move it, so that you can put it back later.  
 Also pull off the airhose from the air box to the core support. run warm ass air into the engine..
  Try to run it at  1850 RPm maybe as you are really close. HTH, tell us how you did and what worked.
 I got MGBs. TR6s etc  thru  FL. state test this way.  Not any more. test gone.