I failed emissions. What do the #'s mean and what can i do?

[Jean]

I'm a little rusty on my emissions analyzing, but everything looks pretty normal. I'd definitely check for vacuum leaks even though your O2 doesn't look terribly high. Change the oil, fill up with a fresh tank of premium gas, change your plugs, try a can of seafoam to clear out carbon, and try again. I'm not sure if the ignition timing is adjustable on our cars, but if it's overly advanced, that could also cause high NOx.

What's the reason for filling up with higher octane ?

I ask because I read an article that said to fill up with low octane for higher burn to help pass emissions.

Taking mine in for a smog on wednesday.

[surebimmer]

eBay item 230175003880 $71 shipped o2 sensor

[Vicarious]

i just noticed that my car missfires also, did the paper to the exhaust trick. it flapped pretty nicely.

So i KNOW i need to replace all the 17 yr old cracked hoses. Now i need to check whats causing that missfire, might be a foulded plug/ig. wire.

I have no way of checking if its the O2 or the Cat or both. Would a code tool be able to tell me this? If i took it to a shop i know, would the mechanic be able to tell me whats up?

[kellie]

Your CO2 is pretty high which indicates that your car is probably running pretty well (right?). I think your next step should be to buy a new cat. If yours is rattling like you said, that should be enough of an indicator that it's time for a new one.

[Vicarious]

Ok i got tested again a few weeks ago, and although the numbers are a little better, they are still nowhere near passing.

All i did was new sparks, oil change, taped upu some vaccum cracks because i couldnt get new hoses in time, had to order.

here are the #'s now:

NOx: 2572
HC: 167
CO%: 0.75
CO2%:13.8
O2%: 0.9

I was thinking of doing Seafoam, get the vac lines finally. I can't realy afford a new O2 sensor at the moment. And plus the exhasut part from the headers to the cat looks new, so does the cat. Could it be possible that whoever did the exhaust reused the O2 sensor? I can't really afford one, theyre like $100.

[thereisnoyun]

cat is last

Check the most important sending units to make sure its functional

- ignition - wire, coil
- vacuum leak
- throttle adjustment
- temperture sending unit
- o2 sensor

these are the top things that screw up emissions. Then seafoam the car and get g2p and you'll pass even with bad cat, unless its totally melted.

[dark89e30]

2 way gets rid of HC and CO and the 3 way adds NOX elimination. 2 way cats are outdated.

[Vicarious]

since when are cats $150? i found $80 ones on jegs or summit. I think im just gonna get a new cat. Mine sounds like someone dropped a penny inside.
Anyone know what best size dimensions to go with for a cat for a 318is? I know its 2.25 in/out, what about length? Does it matter if its oval or sound? Whats the deal with the air inlets? and whats the diff between 2-way and 3-way.

[dark89e30]

Those things alot will definitely drop your nox and but I think that you will be lucky to pass. But I you don't have the $150 for a new cat, I might be worth trying for $20 for a retest.

[NC325iC]

i doubt those things will do much of anything to help your scores, but thats just me

[Vicarious]

Yea, i need to change the valve cover gasket, when i do that i'm also chanign the spark plugs, and putting in new oil. Plan to drive the shit out of it before i go back to take the test again. Should be fine right? I'll try the iso alcohol, but if your saying that my cat is bad anyway, then would those things even do anythhign?

[dark89e30]

Rule of thumb, a new cat will make the car pass almost every time. Try pouring a bottle of isoprophyl alcohol(99%) in your tank, thats all that the smog pass additive is anyway, and that will raise the fuel octane and help drop the nox. With how abnormally high the nox is, and since your C02 is awsome, I can almost guarantee that the cat is bad anyway.

[NC325iC]

guess your smarter with emmisions than i am, last time i failed my HC was in the 300s, o2 sensor replaced fixed it, that was my last emmisions inspection

[kellie]

I'm a little rusty on my emissions analyzing, but everything looks pretty normal. I'd definitely check for vacuum leaks even though your O2 doesn't look terribly high. Change the oil, fill up with a fresh tank of premium gas, change your plugs, try a can of seafoam to clear out carbon, and try again. I'm not sure if the ignition timing is adjustable on our cars, but if it's overly advanced, that could also cause high NOx.

[Vicarious]

ok.
NOx: 2909
HC: 178
CO%: .64 (Pass)
CO2%: 13
O2%: 1.1
RPM 0.

This is exactly how it looks on the print out he gave me. This is NJ inspection by the way.