bllsht

In message <5tednX-pnK9Uyi_ZnZ2dnUVZ_rSdnZ2d@ez2.net>, "Jeff Strickland" wrote:

>
>"Lon" <lon.stowell@comcast.net> wrote in message
>news:0fGdndBxBuElpyzZnZ2dnUVZ_vGdnZ2d@comcast.com ...
>> Pretty much anything that raises the combustion temperature is a suspect
>> for high NOX.
>
>
>High temps _lower_ the NOX.

_Wrong_ NOx is formed when combustion temp is high.

>
>
>
>
>
>Crapped out cat, possibly just running too lean. If a
>> good run takes it under the limit, figure you'll want to check/replace the
>> cat before the next bi-annual.
>
>I agree with that.
>
>
>
>The smog stations are supposed to
>> let the engine cool down before testing, but even the test only stations
>> seem to want you in and out asap.

'Cool down' is a bit misleading. They don't want you 'preconditioning' the
vehicle by trying to heat up the cat, but the vehicle needs to be tested at
normal operating temperature. So, you're supposed to let it idle until up to
temp. The idea is that they've allowed enough time in the test for the cat to
'heat up' while the loaded mode test is running. If it doesn't, there's
something wrong.

A 'cool' cat converter is a sure way to fail for high NOx emissions, since the
cat needs to be hot to rip the nitrogen loose from the oxygen. Too much O2 can
also reduce the cat's ability to reduce NOx, so an exhaust leak upstream of the
cat can cause problems too.

>>
>
>My car failed the low speed test, but passed the high speed test. It left me
>wondering why they do the low speed first on a cold engine when if they do
>the test on a hot engine, it will pass. If the high speed test was done
>first, the engine would come to temp and pass on the low speed test.

The engine is supposed to be at normal operating temp before the test begins.

>
>
>

bllsht

In message <5tednX-pnK9Uyi_ZnZ2dnUVZ_rSdnZ2d@ez2.net>, "Jeff Strickland" wrote:

>
>"Lon" <lon.stowell@comcast.net> wrote in message
>news:0fGdndBxBuElpyzZnZ2dnUVZ_vGdnZ2d@comcast.com ...
>> Pretty much anything that raises the combustion temperature is a suspect
>> for high NOX.
>
>
>High temps _lower_ the NOX.

_Wrong_ NOx is formed when combustion temp is high.

>
>
>
>
>
>Crapped out cat, possibly just running too lean. If a
>> good run takes it under the limit, figure you'll want to check/replace the
>> cat before the next bi-annual.
>
>I agree with that.
>
>
>
>The smog stations are supposed to
>> let the engine cool down before testing, but even the test only stations
>> seem to want you in and out asap.

'Cool down' is a bit misleading. They don't want you 'preconditioning' the
vehicle by trying to heat up the cat, but the vehicle needs to be tested at
normal operating temperature. So, you're supposed to let it idle until up to
temp. The idea is that they've allowed enough time in the test for the cat to
'heat up' while the loaded mode test is running. If it doesn't, there's
something wrong.

A 'cool' cat converter is a sure way to fail for high NOx emissions, since the
cat needs to be hot to rip the nitrogen loose from the oxygen. Too much O2 can
also reduce the cat's ability to reduce NOx, so an exhaust leak upstream of the
cat can cause problems too.

>>
>
>My car failed the low speed test, but passed the high speed test. It left me
>wondering why they do the low speed first on a cold engine when if they do
>the test on a hot engine, it will pass. If the high speed test was done
>first, the engine would come to temp and pass on the low speed test.

The engine is supposed to be at normal operating temp before the test begins.

>
>
>

Jeff Strickland

"bllsht" <nospam@invaliddot.net> wrote in message
news:2dv8b294ltb56fmlcnjomrb308i16rbv70@4ax.com...
> In message <5tednX-pnK9Uyi_ZnZ2dnUVZ_rSdnZ2d@ez2.net>, "Jeff Strickland"
> wrote:
>
>>
>>"Lon" <lon.stowell@comcast.net> wrote in message
>>news:0fGdndBxBuElpyzZnZ2dnUVZ_vGdnZ2d@comcast.co m...
>>> Pretty much anything that raises the combustion temperature is a suspect
>>> for high NOX.
>>
>>
>>High temps _lower_ the NOX.
>
> _Wrong_ NOx is formed when combustion temp is high.


Sorry, I was thinking that high CAT temps was the goal of having a "hot"
engine during a smog test. High CAT Temps _lower_ the NOx readings.




>
>>
>>
>>
>>
>>
>>Crapped out cat, possibly just running too lean. If a
>>> good run takes it under the limit, figure you'll want to check/replace
>>> the
>>> cat before the next bi-annual.
>>
>>I agree with that.
>>
>>
>>
>>The smog stations are supposed to
>>> let the engine cool down before testing, but even the test only stations
>>> seem to want you in and out asap.
>
> 'Cool down' is a bit misleading. They don't want you 'preconditioning'
> the
> vehicle by trying to heat up the cat, but the vehicle needs to be tested
> at
> normal operating temperature. So, you're supposed to let it idle until up
> to
> temp. The idea is that they've allowed enough time in the test for the
> cat to
> 'heat up' while the loaded mode test is running. If it doesn't, there's
> something wrong.
>
> A 'cool' cat converter is a sure way to fail for high NOx emissions, since
> the
> cat needs to be hot to rip the nitrogen loose from the oxygen. Too much
> O2 can
> also reduce the cat's ability to reduce NOx, so an exhaust leak upstream
> of the
> cat can cause problems too.
>

Which is what I said earlier. One wants the CAT to be hot in order to keep
NOx numbers low.



>>>
>>
>>My car failed the low speed test, but passed the high speed test. It left
>>me
>>wondering why they do the low speed first on a cold engine when if they do
>>the test on a hot engine, it will pass. If the high speed test was done
>>first, the engine would come to temp and pass on the low speed test.
>
> The engine is supposed to be at normal operating temp before the test
> begins.
>
>>
>>
>>

Jeff Strickland

"bllsht" <nospam@invaliddot.net> wrote in message
news:2dv8b294ltb56fmlcnjomrb308i16rbv70@4ax.com...
> In message <5tednX-pnK9Uyi_ZnZ2dnUVZ_rSdnZ2d@ez2.net>, "Jeff Strickland"
> wrote:
>
>>
>>"Lon" <lon.stowell@comcast.net> wrote in message
>>news:0fGdndBxBuElpyzZnZ2dnUVZ_vGdnZ2d@comcast.co m...
>>> Pretty much anything that raises the combustion temperature is a suspect
>>> for high NOX.
>>
>>
>>High temps _lower_ the NOX.
>
> _Wrong_ NOx is formed when combustion temp is high.


Sorry, I was thinking that high CAT temps was the goal of having a "hot"
engine during a smog test. High CAT Temps _lower_ the NOx readings.




>
>>
>>
>>
>>
>>
>>Crapped out cat, possibly just running too lean. If a
>>> good run takes it under the limit, figure you'll want to check/replace
>>> the
>>> cat before the next bi-annual.
>>
>>I agree with that.
>>
>>
>>
>>The smog stations are supposed to
>>> let the engine cool down before testing, but even the test only stations
>>> seem to want you in and out asap.
>
> 'Cool down' is a bit misleading. They don't want you 'preconditioning'
> the
> vehicle by trying to heat up the cat, but the vehicle needs to be tested
> at
> normal operating temperature. So, you're supposed to let it idle until up
> to
> temp. The idea is that they've allowed enough time in the test for the
> cat to
> 'heat up' while the loaded mode test is running. If it doesn't, there's
> something wrong.
>
> A 'cool' cat converter is a sure way to fail for high NOx emissions, since
> the
> cat needs to be hot to rip the nitrogen loose from the oxygen. Too much
> O2 can
> also reduce the cat's ability to reduce NOx, so an exhaust leak upstream
> of the
> cat can cause problems too.
>

Which is what I said earlier. One wants the CAT to be hot in order to keep
NOx numbers low.



>>>
>>
>>My car failed the low speed test, but passed the high speed test. It left
>>me
>>wondering why they do the low speed first on a cold engine when if they do
>>the test on a hot engine, it will pass. If the high speed test was done
>>first, the engine would come to temp and pass on the low speed test.
>
> The engine is supposed to be at normal operating temp before the test
> begins.
>
>>
>>
>>

Jeff Strickland

"bllsht" <nospam@invaliddot.net> wrote in message
news:2dv8b294ltb56fmlcnjomrb308i16rbv70@4ax.com...
> In message <5tednX-pnK9Uyi_ZnZ2dnUVZ_rSdnZ2d@ez2.net>, "Jeff Strickland"
> wrote:
>
>>
>>"Lon" <lon.stowell@comcast.net> wrote in message
>>news:0fGdndBxBuElpyzZnZ2dnUVZ_vGdnZ2d@comcast.co m...
>>> Pretty much anything that raises the combustion temperature is a suspect
>>> for high NOX.
>>
>>
>>High temps _lower_ the NOX.
>
> _Wrong_ NOx is formed when combustion temp is high.


Sorry, I was thinking that high CAT temps was the goal of having a "hot"
engine during a smog test. High CAT Temps _lower_ the NOx readings.




>
>>
>>
>>
>>
>>
>>Crapped out cat, possibly just running too lean. If a
>>> good run takes it under the limit, figure you'll want to check/replace
>>> the
>>> cat before the next bi-annual.
>>
>>I agree with that.
>>
>>
>>
>>The smog stations are supposed to
>>> let the engine cool down before testing, but even the test only stations
>>> seem to want you in and out asap.
>
> 'Cool down' is a bit misleading. They don't want you 'preconditioning'
> the
> vehicle by trying to heat up the cat, but the vehicle needs to be tested
> at
> normal operating temperature. So, you're supposed to let it idle until up
> to
> temp. The idea is that they've allowed enough time in the test for the
> cat to
> 'heat up' while the loaded mode test is running. If it doesn't, there's
> something wrong.
>
> A 'cool' cat converter is a sure way to fail for high NOx emissions, since
> the
> cat needs to be hot to rip the nitrogen loose from the oxygen. Too much
> O2 can
> also reduce the cat's ability to reduce NOx, so an exhaust leak upstream
> of the
> cat can cause problems too.
>

Which is what I said earlier. One wants the CAT to be hot in order to keep
NOx numbers low.



>>>
>>
>>My car failed the low speed test, but passed the high speed test. It left
>>me
>>wondering why they do the low speed first on a cold engine when if they do
>>the test on a hot engine, it will pass. If the high speed test was done
>>first, the engine would come to temp and pass on the low speed test.
>
> The engine is supposed to be at normal operating temp before the test
> begins.
>
>>
>>
>>

Norman

"Jeff Strickland" <crwlr@yahoo.com> wrote in message
news:x-CdnUAsDoz4EijZnZ2dnUVZ_tadnZ2d@ez2.net...
>
> "bllsht" <nospam@invaliddot.net> wrote in message
> news:2dv8b294ltb56fmlcnjomrb308i16rbv70@4ax.com...
> > In message <5tednX-pnK9Uyi_ZnZ2dnUVZ_rSdnZ2d@ez2.net>, "Jeff Strickland"
> > wrote:
> >
> >>
> >>"Lon" <lon.stowell@comcast.net> wrote in message
> >>news:0fGdndBxBuElpyzZnZ2dnUVZ_vGdnZ2d@comcast.co m...
> >>> Pretty much anything that raises the combustion temperature is a
suspect
> >>> for high NOX.
> >>
> >>
> >>High temps _lower_ the NOX.
> >
> > _Wrong_ NOx is formed when combustion temp is high.
>
>
> Sorry, I was thinking that high CAT temps was the goal of having a "hot"
> engine during a smog test. High CAT Temps _lower_ the NOx readings.
>
>
>
>
> >
> >>
> >>
> >>
> >>
> >>
> >>Crapped out cat, possibly just running too lean. If a
> >>> good run takes it under the limit, figure you'll want to check/replace
> >>> the
> >>> cat before the next bi-annual.
> >>
> >>I agree with that.
> >>
> >>
> >>
> >>The smog stations are supposed to
> >>> let the engine cool down before testing, but even the test only
stations
> >>> seem to want you in and out asap.
> >
> > 'Cool down' is a bit misleading. They don't want you 'preconditioning'
> > the
> > vehicle by trying to heat up the cat, but the vehicle needs to be tested
> > at
> > normal operating temperature. So, you're supposed to let it idle until
up
> > to
> > temp. The idea is that they've allowed enough time in the test for the
> > cat to
> > 'heat up' while the loaded mode test is running. If it doesn't, there's
> > something wrong.
> >
> > A 'cool' cat converter is a sure way to fail for high NOx emissions,
since
> > the
> > cat needs to be hot to rip the nitrogen loose from the oxygen. Too much
> > O2 can
> > also reduce the cat's ability to reduce NOx, so an exhaust leak upstream
> > of the
> > cat can cause problems too.
> >
>
> Which is what I said earlier. One wants the CAT to be hot in order to keep
> NOx numbers low.
>
>
>
> >>>
> >>
> >>My car failed the low speed test, but passed the high speed test. It
left
> >>me
> >>wondering why they do the low speed first on a cold engine when if they
do
> >>the test on a hot engine, it will pass. If the high speed test was done
> >>first, the engine would come to temp and pass on the low speed test.
> >
> > The engine is supposed to be at normal operating temp before the test
> > begins.
> >
---------------------------------------

You all just made me happy that my 1982 CJ-7 passed emissions in Washington
state for the final time with a header, Howell fuel injection and no smog
pump on the original/rebuilt 258 engine at 220,000 miles.

Pleased,
Norman

Norman

"Jeff Strickland" <crwlr@yahoo.com> wrote in message
news:x-CdnUAsDoz4EijZnZ2dnUVZ_tadnZ2d@ez2.net...
>
> "bllsht" <nospam@invaliddot.net> wrote in message
> news:2dv8b294ltb56fmlcnjomrb308i16rbv70@4ax.com...
> > In message <5tednX-pnK9Uyi_ZnZ2dnUVZ_rSdnZ2d@ez2.net>, "Jeff Strickland"
> > wrote:
> >
> >>
> >>"Lon" <lon.stowell@comcast.net> wrote in message
> >>news:0fGdndBxBuElpyzZnZ2dnUVZ_vGdnZ2d@comcast.co m...
> >>> Pretty much anything that raises the combustion temperature is a
suspect
> >>> for high NOX.
> >>
> >>
> >>High temps _lower_ the NOX.
> >
> > _Wrong_ NOx is formed when combustion temp is high.
>
>
> Sorry, I was thinking that high CAT temps was the goal of having a "hot"
> engine during a smog test. High CAT Temps _lower_ the NOx readings.
>
>
>
>
> >
> >>
> >>
> >>
> >>
> >>
> >>Crapped out cat, possibly just running too lean. If a
> >>> good run takes it under the limit, figure you'll want to check/replace
> >>> the
> >>> cat before the next bi-annual.
> >>
> >>I agree with that.
> >>
> >>
> >>
> >>The smog stations are supposed to
> >>> let the engine cool down before testing, but even the test only
stations
> >>> seem to want you in and out asap.
> >
> > 'Cool down' is a bit misleading. They don't want you 'preconditioning'
> > the
> > vehicle by trying to heat up the cat, but the vehicle needs to be tested
> > at
> > normal operating temperature. So, you're supposed to let it idle until
up
> > to
> > temp. The idea is that they've allowed enough time in the test for the
> > cat to
> > 'heat up' while the loaded mode test is running. If it doesn't, there's
> > something wrong.
> >
> > A 'cool' cat converter is a sure way to fail for high NOx emissions,
since
> > the
> > cat needs to be hot to rip the nitrogen loose from the oxygen. Too much
> > O2 can
> > also reduce the cat's ability to reduce NOx, so an exhaust leak upstream
> > of the
> > cat can cause problems too.
> >
>
> Which is what I said earlier. One wants the CAT to be hot in order to keep
> NOx numbers low.
>
>
>
> >>>
> >>
> >>My car failed the low speed test, but passed the high speed test. It
left
> >>me
> >>wondering why they do the low speed first on a cold engine when if they
do
> >>the test on a hot engine, it will pass. If the high speed test was done
> >>first, the engine would come to temp and pass on the low speed test.
> >
> > The engine is supposed to be at normal operating temp before the test
> > begins.
> >
---------------------------------------

You all just made me happy that my 1982 CJ-7 passed emissions in Washington
state for the final time with a header, Howell fuel injection and no smog
pump on the original/rebuilt 258 engine at 220,000 miles.

Pleased,
Norman

Norman

"Jeff Strickland" <crwlr@yahoo.com> wrote in message
news:x-CdnUAsDoz4EijZnZ2dnUVZ_tadnZ2d@ez2.net...
>
> "bllsht" <nospam@invaliddot.net> wrote in message
> news:2dv8b294ltb56fmlcnjomrb308i16rbv70@4ax.com...
> > In message <5tednX-pnK9Uyi_ZnZ2dnUVZ_rSdnZ2d@ez2.net>, "Jeff Strickland"
> > wrote:
> >
> >>
> >>"Lon" <lon.stowell@comcast.net> wrote in message
> >>news:0fGdndBxBuElpyzZnZ2dnUVZ_vGdnZ2d@comcast.co m...
> >>> Pretty much anything that raises the combustion temperature is a
suspect
> >>> for high NOX.
> >>
> >>
> >>High temps _lower_ the NOX.
> >
> > _Wrong_ NOx is formed when combustion temp is high.
>
>
> Sorry, I was thinking that high CAT temps was the goal of having a "hot"
> engine during a smog test. High CAT Temps _lower_ the NOx readings.
>
>
>
>
> >
> >>
> >>
> >>
> >>
> >>
> >>Crapped out cat, possibly just running too lean. If a
> >>> good run takes it under the limit, figure you'll want to check/replace
> >>> the
> >>> cat before the next bi-annual.
> >>
> >>I agree with that.
> >>
> >>
> >>
> >>The smog stations are supposed to
> >>> let the engine cool down before testing, but even the test only
stations
> >>> seem to want you in and out asap.
> >
> > 'Cool down' is a bit misleading. They don't want you 'preconditioning'
> > the
> > vehicle by trying to heat up the cat, but the vehicle needs to be tested
> > at
> > normal operating temperature. So, you're supposed to let it idle until
up
> > to
> > temp. The idea is that they've allowed enough time in the test for the
> > cat to
> > 'heat up' while the loaded mode test is running. If it doesn't, there's
> > something wrong.
> >
> > A 'cool' cat converter is a sure way to fail for high NOx emissions,
since
> > the
> > cat needs to be hot to rip the nitrogen loose from the oxygen. Too much
> > O2 can
> > also reduce the cat's ability to reduce NOx, so an exhaust leak upstream
> > of the
> > cat can cause problems too.
> >
>
> Which is what I said earlier. One wants the CAT to be hot in order to keep
> NOx numbers low.
>
>
>
> >>>
> >>
> >>My car failed the low speed test, but passed the high speed test. It
left
> >>me
> >>wondering why they do the low speed first on a cold engine when if they
do
> >>the test on a hot engine, it will pass. If the high speed test was done
> >>first, the engine would come to temp and pass on the low speed test.
> >
> > The engine is supposed to be at normal operating temp before the test
> > begins.
> >
---------------------------------------

You all just made me happy that my 1982 CJ-7 passed emissions in Washington
state for the final time with a header, Howell fuel injection and no smog
pump on the original/rebuilt 258 engine at 220,000 miles.

Pleased,
Norman