Failed Smog :-(


Raynman

15+ Year Member

Joined
Aug 2, 2008
Messages
30
Points
3,101
City
Bay Area, Northern CA
Vehicle Year
1999
Transmission
Automatic
Failed Smog Check In California!!! :fie:Last check... ( 2 yrs ago) I replaced cat,o2 sensor ( only one in my vehicle) and that did it. I bought a code reader and got these codes: 157-MAF fault, low voltage 172-HEGO sensor fault lean 173-HEGO sensor fault rich ( does this seem weird, both lean and rich) also, 176 - HEGO sensor fault always lean....also code 189- HEGO sensor fault unable to switch/lean during part throttle....why is HEGO ( o2 sensor) coming up with all these codes??....it's only 2 years old!!! And, last code was 212-loss of ignition diagnostic monitor signal/SPOUT circuit grounded. Where do I start?? I knew my coolant temp sensor was bad, so I am changing that. I will also install set of plugs, clean MAF, Change oil, and see. I really could use some insight if "DieHardFord" is out there, or any other SMOG experts!!! Please Chime in!!!!
 
HA ha

Ha ha, sorry, here in Douglas county Nevada we don't need no stinkin smog check :tease: EVER! :idiot:
 
Thank-you ?

:huh: Thanks, Carlos for the "Ha-Ha" I guess since you never do smog checks, you wouldn't know what to try to correct these codes? Or do you? I'm happy for you that Nevada has no smog laws, though.
 
sorry I'm not sure but maybe if you add more info about the truck. Like what year, motor, trans, and any mods. someone can help point you in the right direction. hope somebody can help you.
 
What were your gas readings when it was tested? I am assuming you are running a 2.9 V6 in your 92 Ranger, but please clarify. O2 sensors can go bad after relatively short periods of time. The aftermarket sensors are not always the best answer as a result of price sensitive markets. You may want to get a sensor range charge for your truck and test the circuits and sensors with a DVOM. That way you'll know if the problem is the sensor or the wiring to it.
 
Readings, Specs.

My truck is a 1992 3.0 Automatic, No A/C The readings from the test are:

@15 Mph/1881rpm @25 Mph/1860 rpm

%CO2 13.3 11.9
%O2 0.3 0.0
HC(ppm): 256 304
co % 2.28 4.50
NO(ppm) 629 516

Hope this clarifies my situation...............
 
Just anther reason to move from California! Ohio has smog checks but not in Columbus. They have been announcing "air quality alerts the last few years on the news, so I figure that their trying to get it started here as well!
:bsflag:
 
Raynman said:
My truck is a 1992 3.0 Automatic, No A/C The readings from the test are:

@15 Mph/1881rpm @25 Mph/1860 rpm

%CO2 13.3 11.9
%O2 0.3 0.0
HC(ppm): 256 304
co % 2.28 4.50
NO(ppm) 629 516

Hope this clarifies my situation...............
Click to expand...

OK, doesn't seem to be any smog experts answering yet and I'm not one either...however, having my Ranger fail the test a few times gives me idea what to look for. Unfortunately, with the numbers you posted and my lack of information on CA testing standards, the information on the test criteria would perhaps be more helpful.

What failed, and if you have them handy, what are the limits of the test criteria (it's usually printed on the sheet and if not it might help to know how far out of spec you were). Typically, the test information also gives you a few hints as to what is causing the failure and can actually be very helpful in taking corrective action.

And for my 2¢ worth, my Ranger failed on HC by a few notches only...and that was due to the carb setup that my truck has (and lack of a working air pump).

Hope this helps clarify a bit more...
 
Failed Smog test: Test Results...

Ok...here is the actual test results....after a tutorial on uploading photos..hope this can get me some insight as to what to fix...I appreciate any help. P.S. I grew up in Michigan, and visited Ohio often...Sandusky for Cedar Point Mostly. I don't miss the snow though !!!

OK..here goes:http://farm4.static.flickr.com/3173/2734727988_6e083c2d9f_b.jpg
 
Again...limited knowledge of this...however...

Your test score indicates HC (unburned gas) and CO (carbon monoxide) are out of spec. They both indicate the result of not burning the fuel properly and can be caused by either getting too much gas for the spark to burn off completely or your not getting proper spark/timing/ or enough air in the mixture.

The MAF error might be the sole cause of the problem...*(Edit) since this measures the amount of air getting into the engine and feeds the ECU along with the O2 sensor*...the link below should explain the sensor and may give you a better idea about why you're getting the other codes...and how it relates to rich/lean conditions if the sensor is wonky...

http://en.wikipedia.org/wiki/Mass_flow_sensor

These are usually expensive sensors if you buy them new...you can try going to the junkyard and pulling one from a similar vehicle...they are plentiful in the yards and cheap...once you replace that check the codes again...if you're still getting errors or a different set of errors then you may need to dig a bit more...

Sounds like you may have a simple fix though...hopefully...

*Edit 2: The MAF on the 2.3 is usually located right at the top of the firewall near the passenger side...about the size of a small cell phone with two wires and a vac hose attached to it...not hard to remove or install...
 
Last edited:
MAF Sensor...

I did CLEAN the MAF sensor, and new plugs, wires cap, rotor. I also knew the coolant temp sensor was bad, and replaced that. Should I try to Clear the codes now, and drive it for awhile and see? One difference is my CEL doesn't come on now like it did before ( used to come on every 15-30 minutes and stay on for around 30-60 secs.) Now, it stays off. How do you clear the codes?
 
with a code reader, ther is a clear function on 99% of them
 
Dang, Cali has some tight restrictions. I would think only a LEV vehicle or better would pass.
 
Unhooking the battery is the inexpensive way and that works as long as you leave it off long enough for the memory to die (like dusty said...2 minutes or longer)...

Once you clear the codes, if you are still getting errors maybe try posting them again and someone here with a bit more experience with codes (my truck doesn't throw codes that I know of)...i had a test on my Tempo and it gave three codes...MAF was the first one and replacing that cleared the other codes up completely...but it was running fine except for intermittent bucking and stalling...(so I guess it wasn't really fine)...
 
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