Failed Smog Test

[wagonmaster69]

I have a 99 explorer V6 OHV.
Took it to have it smog check and it failed.
It passed all the test except OBD system check it has the PO171 system too lean (bank1) and PO174 system too lean (bank 2)
Now my check engine light was on will that make it automatically fail?

 

[lobo411]

Now my check engine light was on will that make it automatically fail?

Absolutely. Automatic fail.

How long has the CEL been on? Try clearing the code and driving it around for a bit. If the code comes back, you have to fix the underlying issue. If not, you might just be able to slip it through smog.

 

[wagonmaster69]

It's been on for a while I replace all the O2 sensors and the EGR valve.
It runs fine and on the "Idle Emission Test Results" it passed.

 

[lobo411]

It's been on for a while I replace all the O2 sensors and the EGR valve.
It runs fine and on the "Idle Emission Test Results" it passed.

Have you checked for a vacuum leak? Maybe the PCV valve?

 

[wagonmaster69]

No I'll look at it this weekend I don't want to pay the shop $75. just to fix a bs problem.

 

[jprentice94]

In ca a check engine light is auto fail

 

[bill06447]

In ca a check engine light is auto fail

In CT it's an auto fail as well. These two codes should be copyrighted by Ford, they are so common, lol. Go to http://www.aa1car.com/library/ford_lean_codes.htm and do the simple checks first before throwing money blindly at your truck.

Bill

 

[koda2000]

check engine light ON = fail. check engine light not working = fail.

 

[1998Exp]

check engine light reset just before the test = fail (at least here)

check engine light ON = fail. check engine light not working = fail.

 

[lobo411]

check engine light reset just before the test = fail (at least here)

Last time I had to get smogged, I had a CEL with P0420. I cleared the code the morning of, then drove the car on the highway and side streets for about 30 mins. Took the car for smogging and passed (just barely on NOx unfortunately, but I passed). This is under Smog Check II--the dyno test w/ the strictest requirements in Southern CA.

Later I replaced my upstream O2 sensors and P0420 never came back.

 

[sloop]

sure fire guaranteed fix:

remove the cel light bulb

 

[bill06447]

OBD II is done thru the under dash connector. Doesn't matter if the bulb is out or not, it knows. As for the person who claims he reset the light and passed emissions, my guess is that the light remained on after the problem resolved itself and was waiting for the second drive cycle when it was reset. If the problem was still there a pending code would have been set and a "fail" would have occurred.

Bill

 

[Dave 1955]

OBD II is done thru the under dash connector. Doesn't matter if the bulb is out or not, it knows. As for the person who claims he reset the light and passed emissions, my guess is that the light remained on after the problem resolved itself and was waiting for the second drive cycle when it was reset. If the problem was still there a pending code would have been set and a "fail" would have occurred.

Bill

True story.
That's how it work..at least in NY.

 

[koda2000]

sure fire guaranteed fix:

remove the cel light bulb

you're wrong. if the bulb doesn't light during the bulb check - instant fail. besides like others have pointed out, OBDII will rat you out if there are stored codes or even if the system has been cleared before the test.

 

[RickOTR]

Low fuel pressure from either a dying fuel pump or a bad fuel filter are other causes for the codes. The OHV was famous for lower intake manifold leaks.

 

[sloop]

oh - in texas, they check what is coming from the exhaust - not what the computer says

and it was a joke

 

[nordictom]

as stated, check for vacuum leaks. Look real good at an "pre-formed" bends, they are usually cracked on the inside of the bend.

Per my Smog Tech, "clear the codes, drive the vehicle 30 to 50 miles, going no less of half of tank on the fuel". It should pass after that.


NT

 

[jprentice94]

Mine was obd1 so no plug but they have you pull up and leave it running so no bulb check but my cel wasnt on anywho but im supprised it passed. He said it looked very good on pretest for how old it was

 

[wagonmaster69]

My light came on cause of the EGR valve(on the driver side of intake with the little black cap on the side) The moose whistle thing.
I replace that and all of my O2 sensors.
But I'll still check for leaks this week.

 

[wagonmaster69]

I cleared the codes with my OBDll scanner now lets see if the light comes back on.
I didn't see any bad hoses or lines.