my jeep failed emissions

[bosco01xj]

So I failed emissions. Results came back with an evap leak? My gas cap passed inspection so I'm wondering what else can cause this. Any ideas?

 

[UNCC_99XJ]

EVAP leak should kick on the check engine light pretty darn quickly. Is it on?

 

[bosco01xj]

yes. it came on while i was waiting in line. its been off for the past three days.

 

[Lowrange2]

God, I love South Carolina!

 

[49erRider]

Just swing into autozone and get it scanned. That will help a lot

 

[UNCC_99XJ]

Yup...typically they're categorized on OBD as a "small leak" or a "large leak" and the code should tell you which it is. The bad part is they're not specific at all usually on exactly what part in the evap system is being offensive. Knowing if it's a small leak or a big one can give you an idea if you need to look for something as simple as a cracked hose (small leak), or come up with some trouble shooting techniques of the bigger components (large leak).

 

[UNCC_99XJ]

And just because your gas cap passed a physical inspection, doesn't mean it's still good. I've seen plenty of them that physically look to be good (i.e. the seal doesn't appear to be cracked) yet they are actually bad. If you get a code for a small leak, a new gas cap is a great (and cheap at roughly $10) place to start.

 

[Team Willys]

If it went back off on its own, try to take the test again. The Jeep PCM will turn the light back off if it passes the tests through three consecutive drive cycles. If it comes back on then I would look into it. I HATE EVAP leaks, they are usually a PITA to figure out.

 

[Cottontail]

Bosco, I failed my first time when I bought my '01 with a "gross emissions error."

I traced the lines and found that one of the little rubber boots that plugs into the evaporative canister down by the fuel tank had split and was leaking. I put a new boot on and it solved the issue immediatly. Problem is, they are hard to find. ChryCo isn't making them anymore (when I needed them anyway) and to get just the boot you need to buy all the hard lines and everything. I was quoted $75. You can't just get a piece of rubber tubing either becuase it is tapered, larger at one end than the other. I ended up popping one off a wreck in the PAP yard.

Long shot, but worth a try.

If you have access to a Jeep that has a good fuel cap, pull that one off and use it, just for test purposes. I traced my leak partially by using the fuel cap off my WJ which had been tested as good the month prior, to ensure that it was something other than the cap.

 

[UNCC_99XJ]

How strict/good are the emissions tests in TN? Do they put a fair amount of emphasis on testing things like the gas cap? Reason I ask is because here in NC their "inspection" is nothing more than plugging their computer into the OBDII port. The shop I usually take my Jeep to gets me in and out in about 10-15 minutes.

 

[bosco01xj]

It takes about that long as well. They pressurize the gas cap and also plug in the sensor.

 

[bosco01xj]

Its not the same in every county though. Rutherford is one of the more strict counties in TN when it comes to emissions testing.

 

[bigalpha]

No emissions in Montgomery county.

 

[High2by]

No emissions in Montgomery county.

Shut Up. :moon:

 

[bigalpha]

Don't hate.

 

[UNCC_99XJ]

So they leave it up to the county to decide? It's a standard test for all of NC, regardless of county.

 

[bigalpha]

Yeah. All of TN does not have emissions testing. Lucky for me. Not sure the truck would pass at this point

 

[bosco01xj]

i think there are between 5 and 10 counties that require it. every other county does not. at least that's what i read on dmv.org.

 

[Cottontail]

So, did you get the issue figured out Bosco?

 

[bosco01xj]

not yet. i'm still trying to find out where to order an oem gas cap. i've tried one from autozone and that didnt help.