Failed Califoria smog test.
 

My son's 89 6 cyl.Cherokee just barely failed the Ca. smog test. It
passed the 15 MPH but failed at 25 MPH on the "NO(PPM)" part of the test
(max allowed is 875 PPM.his read 1066 PPM). Anyone have any ideas what
the problem might be?
The mechanic told him it is probably either the O2 sensor or the
catalytic converter.
TIA
--
"Trust me, I do this all the time"
Mike M

Aside from the good advice you already received, I can only add to make
darned sure it has the proper 195 degree thermostat installed. If the
engine isn't warmed up fully to the 195 degree reading, it won't pass
the smog test. Make sure the engine is as hot as possible before
running the test again.

Jerry

Mike M wrote:
> My son's 89 6 cyl.Cherokee just barely failed the Ca. smog test. It
> passed the 15 MPH but failed at 25 MPH on the "NO(PPM)" part of the test
> (max allowed is 875 PPM.his read 1066 PPM). Anyone have any ideas what
> the problem might be?
> The mechanic told him it is probably either the O2 sensor or the
> catalytic converter.
> TIA

--
Jerry Bransford
PP-ASEL N6TAY
See the Geezer Jeep at
http://members.cox.net/jerrypb/

Mike M > wrote in
:

> My son's 89 6 cyl.Cherokee just barely failed the Ca. smog test. It
> passed the 15 MPH but failed at 25 MPH on the "NO(PPM)" part of the test
> (max allowed is 875 PPM.his read 1066 PPM). Anyone have any ideas what
> the problem might be?
> The mechanic told him it is probably either the O2 sensor or the
> catalytic converter.
> TIA

Same thing happened to me. My '88 YJ failed miserably, though. I tried
everything I could think of to get it to pass. Finally I took it in to the
shop. The mechinic had me start it. First thing he came up with is the cat
converter was bad (granted it did sound like a baby rattle). After
replacing the converter and O2 sensor, I passed with reading down around
where they were when my Jeep was new.

Dave

The O2 sensor is under recall. If the vehicle hasn't had the recall
done, it is still a free fix. It then will likely pass...

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's

Mike M wrote:
>
> My son's 89 6 cyl.Cherokee just barely failed the Ca. smog test. It
> passed the 15 MPH but failed at 25 MPH on the "NO(PPM)" part of the test
> (max allowed is 875 PPM.his read 1066 PPM). Anyone have any ideas what
> the problem might be?
> The mechanic told him it is probably either the O2 sensor or the
> catalytic converter.
> TIA
> --
> "Trust me, I do this all the time"
> Mike M

I don't know about CA but here in MD if you spend a certian amount of money
on repairs and the problem isn't fixed you are exluded from additional
testing until the next test cycle. (2yrs in MD i think)

-Brian
91 YJ 4.0



"Mike M" > wrote in message
.. .
> My son's 89 6 cyl.Cherokee just barely failed the Ca. smog test. It
> passed the 15 MPH but failed at 25 MPH on the "NO(PPM)" part of the test
> (max allowed is 875 PPM.his read 1066 PPM). Anyone have any ideas what
> the problem might be?
> The mechanic told him it is probably either the O2 sensor or the
> catalytic converter.
> TIA
> --
> "Trust me, I do this all the time"
> Mike M
>

My car ('94 BMW) failed the low speed NO test. I was told the CAT was
wearing out. I was allowed to drive around the block to heat it up, and it
was immediately retested. It passed the retest, and the numbers were
significantly different.

If they told you your CAT is faililng, I would be inclined to believe them.




"Mike M" > wrote in message
.. .
> My son's 89 6 cyl.Cherokee just barely failed the Ca. smog test. It
> passed the 15 MPH but failed at 25 MPH on the "NO(PPM)" part of the test
> (max allowed is 875 PPM.his read 1066 PPM). Anyone have any ideas what
> the problem might be?
> The mechanic told him it is probably either the O2 sensor or the
> catalytic converter.
> TIA
> --
> "Trust me, I do this all the time"
> Mike M
>

Really??? An '89 is under recall?




"Mike Romain" > wrote in message
...
> The O2 sensor is under recall. If the vehicle hasn't had the recall
> done, it is still a free fix. It then will likely pass...
>
> Mike
> 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
> 88 Cherokee 235 BFG AT's
>
> Mike M wrote:
> >
> > My son's 89 6 cyl.Cherokee just barely failed the Ca. smog test. It
> > passed the 15 MPH but failed at 25 MPH on the "NO(PPM)" part of the test
> > (max allowed is 875 PPM.his read 1066 PPM). Anyone have any ideas what
> > the problem might be?
> > The mechanic told him it is probably either the O2 sensor or the
> > catalytic converter.
> > TIA
> > --
> > "Trust me, I do this all the time"
> > Mike M

You are correct for MD however if it does not pass on the next cycle you
have to spend more money to get it fixed and so on and so on.
HarryS

"Brian" > wrote in message
...
>I don't know about CA but here in MD if you spend a certian amount of money
>on repairs and the problem isn't fixed you are exluded from additional
>testing until the next test cycle. (2yrs in MD i think)
>
> -Brian
> 91 YJ 4.0
>
>
>
> "Mike M" > wrote in message
> .. .
>> My son's 89 6 cyl.Cherokee just barely failed the Ca. smog test. It
>> passed the 15 MPH but failed at 25 MPH on the "NO(PPM)" part of the test
>> (max allowed is 875 PPM.his read 1066 PPM). Anyone have any ideas what
>> the problem might be?
>> The mechanic told him it is probably either the O2 sensor or the
>> catalytic converter.
>> TIA
>> --
>> "Trust me, I do this all the time"
>> Mike M
>>
>
>

Yup, our 88 failed it's first emissions and when they punched it up, the
O2 was under recall. After the recall it passed with low numbers. I
have told this to others and others have posted it. Apparently the 88
to 91's with the renix computer have bad O2 sensors.

Mike

Jeff Strickland wrote:
>
> Really??? An '89 is under recall?
>
> "Mike Romain" > wrote in message
> ...
> > The O2 sensor is under recall. If the vehicle hasn't had the recall
> > done, it is still a free fix. It then will likely pass...
> >
> > Mike
> > 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
> > 88 Cherokee 235 BFG AT's
> >
> > Mike M wrote:
> > >
> > > My son's 89 6 cyl.Cherokee just barely failed the Ca. smog test. It
> > > passed the 15 MPH but failed at 25 MPH on the "NO(PPM)" part of the test
> > > (max allowed is 875 PPM.his read 1066 PPM). Anyone have any ideas what
> > > the problem might be?
> > > The mechanic told him it is probably either the O2 sensor or the
> > > catalytic converter.
> > > TIA
> > > --
> > > "Trust me, I do this all the time"
> > > Mike M

In article >, says...
> Yup, our 88 failed it's first emissions and when they punched it up, the
> O2 was under recall. After the recall it passed with low numbers. I
> have told this to others and others have posted it. Apparently the 88
> to 91's with the renix computer have bad O2 sensors.
>
> Mike

After reading your post I Googled and found this.
http://alldata.com/TSB/04/890417D4.html

So, did you take it to a dealer and get it replaced?
--
"Trust me, I do this all the time"
Mike M