RyanPerrella

The S4 is now in Sunny but not to hot LA now and i went to get a smog check so i can get a new California title and registration and the car failed. As in Gross polluter failed.

the numbers that are out of line are HC (PPM)
I see max of 108 @ 15 mph mine is 152,
and 83 @ 25mph, mine measures 139

Second issue is NO (PPM)

Max @ 15 is 767 mine measures 2688
max @ 25 is 706 mine is 2631

Interestingly the guy i bought this car from was in San Antonio and i later found out that that stupid county requires no emissions testing. When i registered it in austin i found this out but never tested the car until now. So I am surprised, but its not a surprise that something is out of whack.

Notes: The car has probably 6 month old fuel in it

So, what do i need to do to get my numbers in line. Who's been here before and what had you changed and what did that do for your emissions testing? I need to get the car to pass, but i would like to just correct the issue, wether its one thing, or a couple things. What should i be looking for?

I remember reading that Dr. Bob at one time replaced plugs with the copper ones and saw an improvement in emissions. I have that on the short list, but what else should i be checking?

Would love some suggestions.

RyanPerrella

The car passed visual inspection and functional test, emissions test failed

Also the car was pretty cold. It was sitting then i literally started it up and drove over to the station for the test.

I see in threads the idea of swapping out MAF's, and changing plugs to copper. I also see O2 sensor and cats.

I think I will start with plugs, a universal O2 sensor and not sure what to do about the MAF, maybe a swap of someone else's before sending it out to colorado.

Ideas?

ALSO, the guy mentioned a possible fuel leak somewhere????

RyanPerrella

O2 sensor and plugs will be ordered today, those are cheap enough.

I will run the car till its out of fuel then replace with some good 93, or 92 or 91, whatever they sell here

Oil change was just done, its got mobile 1 15-50 in it now.

For plugs i am going with the Bosch WR7DC

I also see a WR7DC + but have no idea what that is

Rob Edwards

Ryan-

Did they hook up a pressure tester thingee to the filler neck? I would pull the RF wheel and fender liner and have a look at the plastic Y - if it's broken you'll fail the evaporative emissions check.

Make an appt for the smog test, go out and blast around on the 101 in 3rd gear for a while, then show up to the test with the cats pinging hot.

devilinblack

I got lucky. The 78 I just bought passed with flying colors, but he did complain about the gas cap not pressure testing correctly. Jim (I think?) over at 928intl mentioned that the adapters the state uses don't seal well with the caps but I'm not sure if this applies to all years. The guy that tested mine was confused by the locking cap and initially asked if it was a 911 when looking up the info on what he was supposed to look at for the visual inspection.

My only real suggestion would be to echo the comments that it needs to be hot. Make sure it's been at operating temperature for a while and leave it running while waiting for the test, don't shut it down and give it a chance to cool off.

Good Luck!

RyanPerrella

Rob,

The guy didnt pull the wheel off to inspect it.

Not sure about a pressure tester thing.

Here is a pic of the test numbers.

I am trying to compile a parts lest so i can call Jim B and place an order. I was hoping to have numbers so out of line that it would be one of those OBVIOUS issues that i would have to fix. Like someone would see the numbers and immediately think "replace X part" and that would do it.

But i guess i'll start with the plugs, the o2 sensor and go from there, maybe have the MAF rebuilt and so on. I guess i cant sell the car for 3 weeks till i get the new title anyway so i may as well fix the damn thing.

Bill Ball

Jeezuz! Do you have cats on this car? Those are some high numbers for HC and NO. O2 is high too. Maybe you have a very lean miss. Lean raises NO and missing raises HC. Try to get them to do the 25MPH test in a gear that gets the RPM higher. By all means the motor should be hot so the cats are working as best they can. I failed 25MPH HC last time. The test shop allowed me to drive around a while then did the test in lower gear and I passed.

RyanPerrella

what ive learned thus far,

HAVE THE CAR HOT! Mine was sitting for days then i drve it to get tested, total drive time was like 7 minutes

HAVE GOOD GAS! The gas in the tank has got to be months olf, like 5 months now. I havent added gas since i bought it, i never drove the thing.

HAVE COPPER PLUGS! I ordered some new plugs and o2 sensor and should have them tomorrow so i will replace then retest.


Q: Does anyone thats gone the x-pipe route want to sell me their factory cat? I dont want to put anx-pipe on a car i mean to sell.

I dont know if my cats are bad, but i thought i would throw that out there in case.

Bill Ball

Ryan:

What cats do you have on the car? Some of us have had failure of the aftermarket Random Technology cats after only a couple of years. Stock cats on my 89 are still working well enough after 193K miles.

83 928s

Wow man I am in the same boat as you. I did my emissions test at noon today and failed pretty bad also. My HC's were 160, CO% .64, and NO (PPM) was 1259 at 15mph. If I find anything out while researching I will let you know. It also says I failed the Vacuum Lines to Sensors/Switches and failed Ignition timing. Good luck figuring out what to do. Like I said if I figure out anything I will let you know.

Bill51sdr

Agreed with Bill regarding the cats, but man, that engine is running waaaay lean. You have almost no CO emissions/marginal HC which is contributing to the NOX failure big time. Check the output of the o2 sensor before you replace it, see if it is pegged at a high voltage > 0.5V, and not varying. Could indicate the o2 is in fact bad, but the possibilty exists that some other condition is causing the reading.

Richard S

Here's my experience with numbers similar to yours...

https://rennlist.com/forums/928-forum/343625-smog-results-fail-fail-pass-no-more-global-warming.html

Rich

RyanPerrella

I just remembered that a month ago while looking in the CE panel i noticed that the O2 sensor was unplugged. So i plugged it back in. I wonder if it was faulty to the point that it had a detremental effect, or more of a negative effect plugged in then it did simply unplugged.

Regardless i have a new one and should have it on the car tomorrow night along with new plugs.

The cats are factory, but i cant tell you if they are intact or if they hd been hollowed out at all.

I am thinking i will replace plugs and o2 sensor then retest with fresh gas on a hot engine and see where we get then go from there. I would love to avoid testing 100 times but i guess you need to make a modification then retest and so on.

RyanPerrella

Q: Could my cam timing be off? Would that lead to the obvious emissions issue?

I am just trying to find the smoking gun here. It seems to me that its so far off that there must be one OBVIOUS problem here. Not so much a tuning thing as a major obvious issue.

I guess hollow cats could be that smoking gun? Again, anyone want to part with their stock cats?

the flyin' scotsman

Is this the same car you 'sold' in Texas to a guy up here? What happened?