91 Camry.. Barely passed smog test... need suggestions to improve performance

I have a 91 Toyota Camry LE. It has automatic trans, 6 cylinders, and
180k miles. I have taken very good care of it since I purchased it in
92. I recently measured its compression and it read 170 - 175 psi on
all cylinders. I have faithfully changed oil every 3k miles since
its birth.

Last week, I had my car inspected for emissions (in Texas) and I
barely passed the HC portion of the test. Here are my pertinent
results:

Pollutant At High Speed At Low Speed

Standard Reading Standard Reading

HC (ppm) 123 58 128 127
CO (%) .69 .16 .71 .24
CO2 (%) 14.5 14.3

NOx (ppm) 878 437 970 449

As you can see from the results above, I just passed the HC at low
speed. I know that this usually means I have unburned fuel going out
of my exhaust. I don't know what would cause this, especially since
during the past year I have done the following:

1. Changed plugs (platinum, Bosch plugs)
2. Changed plug wires to Toyota OEM wires
3. Cleaned EGR valve
4. Changed PVC valve
5. Changed fuel filter
6. Changed distributor cap

Just before the emissions test, I changed oil and fuel filter. The
air filter has 6k miles on it.

I checked by ear and with propance gas any possible vacuum leaks at
the vacuum hose connections.

I want my vehicle to run as well as possible. I would appreciate some
suggestions on what I might do next.

"Al Kondo" <alkon@hal-pc.org> wrote in message
news:43a17c71.176358600@news.hal-pc.org...[color=blue]
>I have a 91 Toyota Camry LE. It has automatic trans, 6 cylinders, and
> 180k miles. I have taken very good care of it since I purchased it in
> 92. I recently measured its compression and it read 170 - 175 psi on
> all cylinders. I have faithfully changed oil every 3k miles since
> its birth.
>
> Last week, I had my car inspected for emissions (in Texas) and I
> barely passed the HC portion of the test. Here are my pertinent
> results:
>
> Pollutant At High Speed At Low Speed
>
> Standard Reading Standard Reading
>
> HC (ppm) 123 58 128 127
> CO (%) .69 .16 .71 .24
> CO2 (%) 14.5 14.3
>
> NOx (ppm) 878 437 970 449
>
> As you can see from the results above, I just passed the HC at low
> speed. I know that this usually means I have unburned fuel going out
> of my exhaust. I don't know what would cause this, especially since
> during the past year I have done the following:
>
> 1. Changed plugs (platinum, Bosch plugs)
> 2. Changed plug wires to Toyota OEM wires
> 3. Cleaned EGR valve
> 4. Changed PVC valve
> 5. Changed fuel filter
> 6. Changed distributor cap
>
> Just before the emissions test, I changed oil and fuel filter. The
> air filter has 6k miles on it.
>
> I checked by ear and with propance gas any possible vacuum leaks at
> the vacuum hose connections.
>
> I want my vehicle to run as well as possible. I would appreciate some
> suggestions on what I might do next.
>[/color]

The O2 sensors in your exhaust manifold may be marginal. Also, next time
you install spark plugs, install OEM Desno plugs instead of the Bosch plugs.
--
Ray O
correct the return address punctuation to reply

"Ray O" <rokigawa@tristarassociatesDOT.com> wrote in message
news:15031$43a1a7c3$44a4a10d$19991@msgid.meganewsservers.com...[color=blue]
>
> "Al Kondo" <alkon@hal-pc.org> wrote in message
> news:43a17c71.176358600@news.hal-pc.org...[color=green]
>>I have a 91 Toyota Camry LE. It has automatic trans, 6 cylinders, and
>> 180k miles. I have taken very good care of it since I purchased it in
>> 92. I recently measured its compression and it read 170 - 175 psi on
>> all cylinders. I have faithfully changed oil every 3k miles since
>> its birth.
>>
>> Last week, I had my car inspected for emissions (in Texas) and I
>> barely passed the HC portion of the test. Here are my pertinent
>> results:
>>
>> Pollutant At High Speed At Low Speed
>>
>> Standard Reading Standard Reading
>>
>> HC (ppm) 123 58 128 127
>> CO (%) .69 .16 .71 .24
>> CO2 (%) 14.5 14.3
>>
>> NOx (ppm) 878 437 970 449
>>
>> As you can see from the results above, I just passed the HC at low
>> speed. I know that this usually means I have unburned fuel going out
>> of my exhaust. I don't know what would cause this, especially since
>> during the past year I have done the following:
>>
>> 1. Changed plugs (platinum, Bosch plugs)
>> 2. Changed plug wires to Toyota OEM wires
>> 3. Cleaned EGR valve
>> 4. Changed PVC valve
>> 5. Changed fuel filter
>> 6. Changed distributor cap
>>
>> Just before the emissions test, I changed oil and fuel filter. The
>> air filter has 6k miles on it.
>>
>> I checked by ear and with propance gas any possible vacuum leaks at
>> the vacuum hose connections.
>>
>> I want my vehicle to run as well as possible. I would appreciate some
>> suggestions on what I might do next.
>>[/color]
>
> The O2 sensors in your exhaust manifold may be marginal. Also, next time
> you install spark plugs, install OEM Desno plugs instead of the Bosch
> plugs.
> --
> Ray O[/color]

Additionally, there may be -nothing- wrong with the car. A marginal HC
reading can easily be a catalyst that was not fully up to operating
temperature ... and/or a catalyst with a lot of miles on it.

--

- Philip

"Philip" <1chip-state1@earthlink.net> wrote in message
news:Fiiof.4956$3Z.307@newsread1.news.atl.earthlink.net...[color=blue]
>
> "Ray O" <rokigawa@tristarassociatesDOT.com> wrote in message
> news:15031$43a1a7c3$44a4a10d$19991@msgid.meganewsservers.com...[color=green]
>>
>> "Al Kondo" <alkon@hal-pc.org> wrote in message
>> news:43a17c71.176358600@news.hal-pc.org...[color=darkred]
>>>I have a 91 Toyota Camry LE. It has automatic trans, 6 cylinders, and
>>> 180k miles. I have taken very good care of it since I purchased it in
>>> 92. I recently measured its compression and it read 170 - 175 psi on
>>> all cylinders. I have faithfully changed oil every 3k miles since
>>> its birth.
>>>
>>> Last week, I had my car inspected for emissions (in Texas) and I
>>> barely passed the HC portion of the test. Here are my pertinent
>>> results:
>>>
>>> Pollutant At High Speed At Low Speed
>>>
>>> Standard Reading Standard Reading
>>>
>>> HC (ppm) 123 58 128 127
>>> CO (%) .69 .16 .71 .24
>>> CO2 (%) 14.5 14.3
>>>
>>> NOx (ppm) 878 437 970 449
>>>
>>> As you can see from the results above, I just passed the HC at low
>>> speed. I know that this usually means I have unburned fuel going out
>>> of my exhaust. I don't know what would cause this, especially since
>>> during the past year I have done the following:
>>>
>>> 1. Changed plugs (platinum, Bosch plugs)
>>> 2. Changed plug wires to Toyota OEM wires
>>> 3. Cleaned EGR valve
>>> 4. Changed PVC valve
>>> 5. Changed fuel filter
>>> 6. Changed distributor cap
>>>
>>> Just before the emissions test, I changed oil and fuel filter. The
>>> air filter has 6k miles on it.
>>>
>>> I checked by ear and with propance gas any possible vacuum leaks at
>>> the vacuum hose connections.
>>>
>>> I want my vehicle to run as well as possible. I would appreciate some
>>> suggestions on what I might do next.
>>>[/color]
>>
>> The O2 sensors in your exhaust manifold may be marginal. Also, next time
>> you install spark plugs, install OEM Desno plugs instead of the Bosch
>> plugs.
>> --
>> Ray O[/color]
>
> Additionally, there may be -nothing- wrong with the car. A marginal HC
> reading can easily be a catalyst that was not fully up to operating
> temperature ... and/or a catalyst with a lot of miles on it.
>
> --
>
> - Philip[/color]

Good point!
--
Ray O
correct the return address punctuation to reply

Echo comment on the Botched spark plugs! Changd the thermostate recently?
It will ensure you car gets to the correct operting temperature.

"Al Kondo" <alkon@hal-pc.org> wrote in message
news:43a17c71.176358600@news.hal-pc.org...[color=blue]
>I have a 91 Toyota Camry LE. It has automatic trans, 6 cylinders, and
> 180k miles. I have taken very good care of it since I purchased it in
> 92. I recently measured its compression and it read 170 - 175 psi on
> all cylinders. I have faithfully changed oil every 3k miles since
> its birth.
>
> Last week, I had my car inspected for emissions (in Texas) and I
> barely passed the HC portion of the test. Here are my pertinent
> results:
>
> Pollutant At High Speed At Low Speed
>
> Standard Reading Standard Reading
>
> HC (ppm) 123 58 128 127
> CO (%) .69 .16 .71 .24
> CO2 (%) 14.5 14.3
>
> NOx (ppm) 878 437 970 449
>
> As you can see from the results above, I just passed the HC at low
> speed. I know that this usually means I have unburned fuel going out
> of my exhaust. I don't know what would cause this, especially since
> during the past year I have done the following:
>
> 1. Changed plugs (platinum, Bosch plugs)
> 2. Changed plug wires to Toyota OEM wires
> 3. Cleaned EGR valve
> 4. Changed PVC valve
> 5. Changed fuel filter
> 6. Changed distributor cap
>
> Just before the emissions test, I changed oil and fuel filter. The
> air filter has 6k miles on it.
>
> I checked by ear and with propance gas any possible vacuum leaks at
> the vacuum hose connections.
>
> I want my vehicle to run as well as possible. I would appreciate some
> suggestions on what I might do next.
>
>
>[/color]