What Do These Smog Numbers Point To?

My '84 Toyota pickup with 155K miles failed smog check today. I'm sure
the numbers tell a story of what's likely to need attention. But I
don't speak the language. So, if you can interpret, I'd appreciate
your adivce.

About the truck, It passed ok a year ago for change of ownership, and
has been driven less than a thousand miles since then. Mostly ten mile
trips to Home Depot on the weekend. In getting ready for the smog
check, I changed the oil & air filter, scoped the ignition & replaced
bad coil & wires, tested the EGR valve (blow & suck through it to
confirm one way action). In retrospect, the temp guage has been
running a little low. Maybe I should have changed the thermostat.

The numbers:

@15 MPH CO2 14.3%, O2 0.5%, HC 251 ppm, CO 0.43%, NO 1173 ppm
@25 MPH CO2 14.8%, O2 0.1%, HC 126 ppm, CO 0.08%, NO 558 ppm

Since I can't see the numbers change as I adjust things like a mixture
screw, a simple adjustment would cost me over $100. I'd rather spend
the $100 on a new catalytic converter if that would do the trick. What
do you think?

Thanks guys.

On Apr 23, 10:35*pm, Wekadog > wrote:
> My '84 Toyota pickup with 155K miles failed smog check today. I'm sure
> the numbers tell a story of what's likely to need attention. But I
> don't speak the language. So, if you can interpret, I'd appreciate
> your adivce.
>
> About the truck, It passed ok a year ago for change of ownership, and
> has been driven less than a thousand miles since then. Mostly ten mile
> trips to Home Depot on the weekend. In getting ready for the smog
> check, I changed the oil & air filter, scoped the ignition & replaced
> bad coil & wires, tested the EGR valve (blow & suck through it to
> confirm one way action). In retrospect, the temp guage has been
> running a little low. Maybe I should have changed the thermostat.
>
> The numbers:
>
> @15 MPH CO2 14.3%, O2 0.5%, HC 251 ppm, CO 0.43%, NO 1173 ppm
> @25 MPH CO2 14.8%, O2 0.1%, HC 126 ppm, CO 0.08%, NO 558 ppm
>
> Since I can't see the numbers change as I adjust things like a mixture
> screw, a simple adjustment would cost me over $100. I'd rather spend
> the $100 on a new catalytic converter if that would do the trick. What
> do you think?
>
> Thanks guys.

if I recall a cooler motor will run richer until it warms up.

Wekadog > wrote in news:83f30327-358b-41a9-9dc2-
:

> My '84 Toyota pickup with 155K miles failed smog check today. I'm sure
> the numbers tell a story of what's likely to need attention. But I
> don't speak the language. So, if you can interpret, I'd appreciate
> your adivce.
>
> About the truck, It passed ok a year ago for change of ownership, and
> has been driven less than a thousand miles since then. Mostly ten mile
> trips to Home Depot on the weekend. In getting ready for the smog
> check, I changed the oil & air filter, scoped the ignition & replaced
> bad coil & wires, tested the EGR valve (blow & suck through it to
> confirm one way action). In retrospect, the temp guage has been
> running a little low. Maybe I should have changed the thermostat.
>
> The numbers:
>
> @15 MPH CO2 14.3%, O2 0.5%, HC 251 ppm, CO 0.43%, NO 1173 ppm
> @25 MPH CO2 14.8%, O2 0.1%, HC 126 ppm, CO 0.08%, NO 558 ppm
>
> Since I can't see the numbers change as I adjust things like a mixture
> screw, a simple adjustment would cost me over $100. I'd rather spend
> the $100 on a new catalytic converter if that would do the trick. What
> do you think?
>
> Thanks guys.



You're high across-the-board. Cat and O2-sensor were not hot enough, I'm
guessing.

Book a test so you're the first one on the machine that morning. Take the
truck for a half-hour drive--preferably at highway speeds--with all
accessories on, including the A/C and rear-window defogger. Arrive at the
test station exactly on time when they open. Do NOT let the truck idle, but
shut it off while waiting.

Bet it passes.

--
Tegger

On Mon, 25 Apr 2011 22:23:37 +0000, Tegger wrote:

> Wekadog > wrote in news:83f30327-358b-41a9-9dc2-
> :
>
>> My '84 Toyota pickup with 155K miles failed smog check today. I'm sure
>> the numbers tell a story of what's likely to need attention. But I don't
>> speak the language. So, if you can interpret, I'd appreciate your
>> adivce.
>>
>> About the truck, It passed ok a year ago for change of ownership, and
>> has been driven less than a thousand miles since then. Mostly ten mile
>> trips to Home Depot on the weekend. In getting ready for the smog check,
>> I changed the oil & air filter, scoped the ignition & replaced bad coil
>> & wires, tested the EGR valve (blow & suck through it to confirm one way
>> action). In retrospect, the temp guage has been running a little low.
>> Maybe I should have changed the thermostat.
>>
>> The numbers:
>>
>> @15 MPH CO2 14.3%, O2 0.5%, HC 251 ppm, CO 0.43%, NO 1173 ppm @25 MPH
>> CO2 14.8%, O2 0.1%, HC 126 ppm, CO 0.08%, NO 558 ppm
>>
>> Since I can't see the numbers change as I adjust things like a mixture
>> screw, a simple adjustment would cost me over $100. I'd rather spend the
>> $100 on a new catalytic converter if that would do the trick. What do
>> you think?
>>
>> Thanks guys.
>
>
>
> You're high across-the-board. Cat and O2-sensor were not hot enough, I'm
> guessing.
>
> Book a test so you're the first one on the machine that morning. Take the
> truck for a half-hour drive--preferably at highway speeds--with all
> accessories on, including the A/C and rear-window defogger. Arrive at the
> test station exactly on time when they open. Do NOT let the truck idle,
> but shut it off while waiting.
>
> Bet it passes.


All I had to do with my Supra was change the spark plugs...

On 04/23/2011 07:35 PM, Wekadog wrote:
> My '84 Toyota pickup with 155K miles failed smog check today. I'm sure
> the numbers tell a story of what's likely to need attention. But I
> don't speak the language. So, if you can interpret, I'd appreciate
> your adivce.
>
> About the truck, It passed ok a year ago for change of ownership, and
> has been driven less than a thousand miles since then. Mostly ten mile
> trips to Home Depot on the weekend. In getting ready for the smog
> check, I changed the oil& air filter, scoped the ignition& replaced
> bad coil& wires, tested the EGR valve (blow& suck through it to
> confirm one way action). In retrospect, the temp guage has been
> running a little low. Maybe I should have changed the thermostat.
>
> The numbers:
>
> @15 MPH CO2 14.3%, O2 0.5%, HC 251 ppm, CO 0.43%, NO 1173 ppm
> @25 MPH CO2 14.8%, O2 0.1%, HC 126 ppm, CO 0.08%, NO 558 ppm
>
> Since I can't see the numbers change as I adjust things like a mixture
> screw, a simple adjustment would cost me over $100. I'd rather spend
> the $100 on a new catalytic converter if that would do the trick. What
> do you think?
>
> Thanks guys.

high NO can be a symptom of excess combustion temperature. if the egr
works correctly, typical candidates are too lean a mix, excessive
deposits in the combustion chamber, etc. or it could just be a dying cat.

don't assume the egr is working right. it's not just a case of whether
you're getting flow, but the /amount/ of it as well. suggest cleaning
it to ensure flow rates are correct.

other than that, i'd replace the cat. none of your figures are that
healthy - they don't last forever.


--
nomina rutrum rutrum

In getting ready for the smog
> check, I changed the oil & air filter, scoped the ignition & replaced
> bad coil & wires, tested the EGR valve (blow & suck through it to
> confirm one way action). In retrospect, the temp guage has been
> running a little low. Maybe I should have changed the thermostat.

Make sure the egr *really* works... does it get vacuum when you 'blip'
the throttle? Does the valve hold vacuum? Does the valve open when
vacuum is applied? Does the RPM drop when the valve is open?
Does it have air injection? If so make triple sure it works.
Do you have the right spark plugs? (not platinum or anything fancy)?
Tightening up the gap to the lower end of spec can
HTH,
Ben