Failed A California Smog...PLEASE HELP!!!j

Vengeance · Jul 12, 2013

Updated 7/19/2013 : Replaced the O2 sensor, bad vacuum line, and coolant temp sensor and it was abble to pass.
--------------------------------------------------------------------------------------------------------------

SO i unfortunately failed a cali smog. I was wondering if you fine individuals could help me identify my problems.

Here's the test results:

______________________________________________________________
%CO2 | %O2 | HC(ppm) ------| CO (%) -----------| NO (ppm)
11.97 | 3.37 | Max=59 Me=65 | Max=0.34 Me=0.03 | Max=484 Me=771-------- 15mph
11.70 | 3.75 | Max=34 Me=42 | Max=0.32 Me=0.01 | Max=498 Me=768 --------25mph

Sooooo as you can see the HC and NO are the two that are killing me here.

The guy at the shop recommended i replace the upstream O2 sensors since they are original. And retest from there, but i don't want to chance it so what else should i check.

I have already replaced: Distributor, plugs, wires when i bought the car last year. The timing is set to B10*....and no CELs

The only issue i find with my car is it takes forever to warm up, i will drive for 15min and the needle will only be at the N on Normal. so could i have a t-stat problem causing the car to run wrong?? maybe??? Do i possibly have a poor operating EGR valve that is not setting off the CEL.

Oh and one other problem i have is that when i drive the car cold the car does not like to rev past 2200-2800rpm, it stutters or sputters or something, but as the car engine warms up this problems goes away?

CC'S95GT · Jul 12, 2013

In Atlanta I have to get tested every year.
I have also had problems passing.
The trick I have used is to pull the spout connector. It will start, run, and drive just like normal up to about 3000 rpm's. then it'll fall on it's face. But the rollers don't need to see that hi of an rpm to test. It passes like it's not even running.
Pulling the spout isn't exactly "legal" but if the tester doesn't know to look under the airbox for it, he'll never know.

BTW, you only have 2 O2 sensors. 1 on each bank before the cats. None after.

You might also replace the thermostat. I'm running a 180* but I think stock is 190*. Running to cool can make it run richer.
Also clean the MAF and inlet temp sensor

toyman · Jul 13, 2013

The O2's are a consumable item good for about 60k miles. They will default rich. Temperature dash needle position doesn't mean much. You need an fairly exact reading to draw useable conclusions about the T-stat and ECT sensor. A clean/working MAF is critical. Also ensure the battery to engine and engine to chassis grounds are solid as the PCM and all sensors are negatively affected by bad grounds.

Vengeance · Jul 13, 2013

CC'S95GT said:
In Atlanta I have to get tested every year.
I have also had problems passing.
The trick I have used is to pull the spout connector. It will start, run, and drive just like normal up to about 3000 rpm's. then it'll fall on it's face. But the rollers don't need to see that hi of an rpm to test. It passes like it's not even running.
Pulling the spout isn't exactly "legal" but if the tester doesn't know to look under the airbox for it, he'll never know.

BTW, you only have 2 O2 sensors. 1 on each bank before the cats. None after.

You might also replace the thermostat. I'm running a 180* but I think stock is 190*. Running to cool can make it run richer.
Also clean the MAF and inlet temp sensor

Unfortunately the spout trick wont work at the shop i go to because he is a big car guy, knows his ish. And he is a friend so i wouldnt do that. but i have checked the maf, looks good and clean, i probably should clean it again thought. thanks for the input

toyman said:
The O2's are a consumable item good for about 60k miles. They will default rich. Temperature dash needle position doesn't mean much. You need an fairly exact reading to draw useable conclusions about the T-stat and ECT sensor. A clean/working MAF is critical. Also ensure the battery to engine and engine to chassis grounds are solid as the PCM and all sensors are negatively affected by bad grounds.

okay so o2s for sure then, is there a way to get a more accurate read of the engine temp other than the interior gauge? Great idea about grounds, i didnt even think of that, my last car had ground issues and f'ed it all up so i will definitely check that.

sn95 bullitt · Jul 13, 2013

Seafoam will do the trick.

toyman · Jul 13, 2013

An infrared thermometer should work. Take a reading on the T-stat housing/ECT housing.

Vengeance · Jul 13, 2013

sn95 bullitt said:
Seafoam will do the trick.

I worry about that stuff, i hear different people have problems sometime.

toyman said:
An infrared thermometer should work. Take a reading on the T-stat housing/ECT housing.

ahh good idea.

So i was tinkering under the hood today, found a line that is very decayed, dont know if it has anything to do with vacuum or not??

sn95 bullitt · Jul 14, 2013

I have never had a problem with it. Made my old stang pass smog both times it failed.

Vengeance · Jul 14, 2013

sn95 bullitt said:
I have never had a problem with it. Made my old stang pass smog both times it failed.

Okay if I try that where would I put the seafoam in? Fuel tank, or vacuum line? I can't do oil because I just changed oil last week.

PikesPeakPony · Jul 14, 2013

Vengeance said:
I worry about that stuff, i hear different people have problems sometime.

ahh good idea.

So i was tinkering under the hood today, found a line that is very decayed, dont know if it has anything to do with vacuum or not??

Thats the solenoid purge valve and yes that can cause it to not pass. my car threw a code for it. the diagnostic handheld said my car was not passing because of the problem. I replaced it and the hoses(which is a b***h) and everything is fine now. I had rotted hoses just like that and a bad solenoid.

sn95 bullitt · Jul 14, 2013

I did vacuum and fuel tank.

Vengeance · Jul 19, 2013

yaaaaaaaa!!! passed today, still i little high on the HC but under the max.

What i did was replaced the vacuum line, coolant temp sensor, and O2 sensors and runs much better and passed yaay.

CC'S95GT · Jul 21, 2013

:thumbsup:

RichV · Jul 21, 2013

Glad you got it to pass.

If you're all stock, timing and plug gaps make huge differences in smog #s. Just make sure it is factory setting and new wires can't hurt either. My old 5.0 had extremely high HC #s (>4), and the problem was plug gaps. I put the gaps to the right settings, tested it like 2 hours after the fail, and the HC was <1.

eeltam · Aug 12, 2013

CC'S95GT said:
In Atlanta I have to get tested every year.
I have also had problems passing.
The trick I have used is to pull the spout connector. It will start, run, and drive just like normal up to about 3000 rpm's. then it'll fall on it's face. But the rollers don't need to see that hi of an rpm to test. It passes like it's not even running.
Pulling the spout isn't exactly "legal" but if the tester doesn't know to look under the airbox for it, he'll never know.

BTW, you only have 2 O2 sensors. 1 on each bank before the cats. None after.

You might also replace the thermostat. I'm running a 180* but I think stock is 190*. Running to cool can make it run richer.
Also clean the MAF and inlet temp sensor

I failed smog today and these are my results. Naturally it can be a number of things. I was wondering if the spout connector trick would work on a 4.6 and if so where is it located? What exactly is the spout connector and why would it help me pass? Also if I do need to replace a cat or o2 sensor what is the best way to check them out. I don't want to replace all if I don't need to. I'm on a very tight budget.

		%c02	%02		hc			co			no
Test	rpm	meas	meas	max	ave	meas	max	ave	meas	max	ave	meas
15mph	1504	14.9	0.01	50	9	34	0.48	0.03	0.06	414	67	739
25mph	1071	15.0	0.0	34	6	43	0.45	0.03	0.06	701	62	315

Oh RED indicates the failure

cobraracer46 · Aug 12, 2013

eeltam said:
I failed smog today and these are my results. Naturally it can be a number of things. I was wondering if the spout connector trick would work on a 4.6 and if so where is it located? What exactly is the spout connector and why would it help me pass? Also if I do need to replace a cat or o2 sensor what is the best way to check them out. I don't want to replace all if I don't need to. I'm on a very tight budget.

%c02 %02 hc co no
Test rpm meas meas max ave meas max ave meas max ave meas
15mph 1504 14.9 0.01 50 9 34 0.48 0.03 0.06 414 67 739
25mph 1071 15.0 0.0 34 6 43 0.45 0.03 0.06 701 62 315

Oh RED indicates the failure

Co2 and o2 #'s look good so It looks like the cats are not working. If you live in California, you will need some expensive CARB certified OBD II cats. 49 state and universal cats are illegal. No spout on 4.6 mustangs by the way.

eeltam · Aug 12, 2013

cobraracer46 said:
Co2 and o2 #'s look good so It looks like the cats are not working. If you live in California, you will need some expensive CARB certified OBD II cats. 49 state and universal cats are illegal. No spout on 4.6 mustangs by the way.

Ok, thanks for the reply. Much appreciated. how can I check the cats to determine which one is bad ?

cobraracer46 · Aug 13, 2013

You will need an exhaust gas analyzer for starters and with that you would give the car a snap acceleration and note the CO2 gain. If the Co2 gain is less than expected, then the cats are bad. You could also drill a hole before the cats and retest the car with the exhaust probe before the cat. If the before and after cat emissions are the same then the cat is bad.

CC'S95GT · Aug 13, 2013

How many miles are on the cats? If they've been on for 100k or more then they're probably due for replacement too. Same goes for the sensors too.
If only 1 is bad then it isn't long till the others clog up as well.
Just replace them all together.