help on SMOG fail results

[stoneyli]

My 1991 Toyota Corolla 1.6L Engine 4 Cyl (<100K) fail ca smog test only check on NO (PPM) @15Mph. If someone could offer some suggestion about what I can do before I go for the retesting, it will be highly appreicated. Thanks.

The test results and my questions are following:

----------------------------------------------------------------------------------------------------
Overall Test Result
Copmprehsive Visual Inspection: Pass; Func check: Pass; Emissions Test:Fail
-----------------------------------------------------------------------------------------------------
Emission Control Sysytem Visual Inspection/Functional Check Results
All pass except the following are N/As:
EGR Visual; EGR Functional; Thermostatic Air Cleaner; Airinjection; Fillpipe Restrictor;
-----------------------------------------------------------------------------------------------------
ASM Emission Test Results
RPM %CO2 O2% HC (PPM) CO (%) NO(PPM) Result
MEAS MEAS Max Ave Meas Max Ave Meas Max Ave Mesa
15mph 1735 12.9 3.1 130 31 31 .8 .1 .13 835 237 975 Fail
25mph 2763 14.1 1.3 105 20 20 .69 .09 .15 774 199 647 Pass

The fail part is:
NO(PPM) @15MPH
Max 835
Ave 237
Mesa 975
However @25MPH pass: 774(max) 199(ave) 647(Mesa)


Before the smog test,
0. Is the O2% too high?
1. did a oil change the day before (allways did that before previous smog);
2. filled gas tank with No87 gas on the way to the test only station
3. drive about 20min to the station locally
4. let the engine off and waiting for the chechk about 10-15min (I did not know I should let it on)
waiting for the previous car to be done
5. never had smog failure previously
Quesitons:
1. what can be done to improve the results?
2. Does the N/A in visual inpsection mean my car does NOT have EGR?

[freakinbox]

N/A means don't worry about it. Usually means they don't test that part for functionality or a visual look at it. As far as I know all the North American cars had EGR valves. I just did a search on google and as usual with smog there are a list of possible culprits

"bad o2 sensor
bad EGR valve
bad cat
bad timing
dirty injectors
bad plugs or wires"

Which is the norm for failing the smog test. Here they offer a test for $80 that apparently tells you what exactly is wrong, But I think on a lot of the older cars it's useless. Every time I ask them no one can ever tell me how it goes about testing all of those things from the tail pipe if I don't have a computer for them to pull codes off of.

Although on my car NO ppm is the only thing I managed to pass at 2600 - 2800 rpm. I will point out though I did change my car and my NO ppm went from 333 to 248. But at least where I am they are one of the more expensive parts to change for the smog test so go with the simple things first.

[voganni]

What a racket smog testing is! Glad I don't need it where I live. My son's old 'rolla failed, in the idle part. A mechanic told him to run it low on gas and put about 3 gallons of ethanol in the tank. Said it would pass with flying colors. He did it with a couple hot rods he built that didn't have a prayer of passing, and they both passed. We haven't tried it yet, but probably will! (soon as we find out where to buy ethanol). Worth a try.

[jc92corolla]

Originally Posted by stoneyli

My 1991 Toyota Corolla 1.6L Engine 4 Cyl (<100K) fail ca smog test only check on NO (PPM) @15Mph. If someone could offer some suggestion about what I can do before I go for the retesting, it will be highly appreicated. Thanks.

The test results and my questions are following:

----------------------------------------------------------------------------------------------------
Overall Test Result
Copmprehsive Visual Inspection: Pass; Func check: Pass; Emissions Test:Fail
-----------------------------------------------------------------------------------------------------
Emission Control Sysytem Visual Inspection/Functional Check Results
All pass except the following are N/As:
EGR Visual; EGR Functional; Thermostatic Air Cleaner; Airinjection; Fillpipe Restrictor;
-----------------------------------------------------------------------------------------------------
ASM Emission Test Results
RPM %CO2 O2% HC (PPM) CO (%) NO(PPM) Result
MEAS MEAS Max Ave Meas Max Ave Meas Max Ave Mesa
15mph 1735 12.9 3.1 130 31 31 .8 .1 .13 835 237 975 Fail
25mph 2763 14.1 1.3 105 20 20 .69 .09 .15 774 199 647 Pass

The fail part is:
NO(PPM) @15MPH
Max 835
Ave 237
Mesa 975
However @25MPH pass: 774(max) 199(ave) 647(Mesa)


Before the smog test,
0. Is the O2% too high?
1. did a oil change the day before (allways did that before previous smog);
2. filled gas tank with No87 gas on the way to the test only station
3. drive about 20min to the station locally
4. let the engine off and waiting for the chechk about 10-15min (I did not know I should let it on)
waiting for the previous car to be done
5. never had smog failure previously
Quesitons:
1. what can be done to improve the results?
2. Does the N/A in visual inpsection mean my car does NOT have EGR?

If you go on line to DMV and search for tips on how to pass smog check . there is alot of information there.There are so many reason for your car to fail smog .When you change the oil , did you change the air filter? . And for the gas is always better to use the premiun or most expensive . good luck ..... JC.

[90 GP]

If you have a highway near you drive at speed to get engine thoroughly warmed up and then go to test station. DO NOT turn off car while waiting in line. You want to keep the catalytic converter and oxygen sensor up to operating temp. Bet you would pass doing just the above.

[stoneyli]

thanks for all the reply. I checked with the smog technician. He said I dont have an EGR and O2% is a little bit high. If there is EGR, that will point to an EGR valve clean up. Since it is not the case, then only if might be a vacum leak. But how can I check vacum leak?

BTW, I found out the air filter is pretty dirty, and I replaced that.
I will try the "garantee to pass" but I need to wait the full tank of gas to run out before I can add it to the tank.
Should I change the spark plug too?

Thanks,