Failed emissions, nox is crazy high
#1
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Car: 1988 GTA
Engine: 5.0 TPI
Transmission: T5
Axle/Gears: 9 Bolt, 3.45
Failed emissions, nox is crazy high
I took my car to get it inspected today, and failed smog miserably. High speed nox was 6811/1014, low speed was 7832/1110. My cat, O2 sensor, and EGR are barely a year old, no check engine light. However, the car did have some 4 month old gas in it, as it's been sitting a while. I put fresh gas in with the old gas, but could that be part of it? I'm gonna go do some datalogging in a bit, and see if anything looks odd. Any suggestions?
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Car: 83 POS monte carlo 2015 chevy P/U
Engine: 92 5.7 tpi 5.3
Transmission: 700r4 6L60E
Axle/Gears: 2.42 too high
Re: Failed emissions, nox is crazy high
WOW! i have never seen NOx that high before.
around 3500 is the highest i've seen, and that was with the timing set too high, no EGR, no cat, and running lean because of a bad fuel pump.
bad gas can cause excessive emissions, so run all the old gas out of it with some super then make sure the timing is right and the EGR is working.
also check it for vacuum leaks, fuel pressure and overheating.
what were the other numbers?
around 3500 is the highest i've seen, and that was with the timing set too high, no EGR, no cat, and running lean because of a bad fuel pump.
bad gas can cause excessive emissions, so run all the old gas out of it with some super then make sure the timing is right and the EGR is working.
also check it for vacuum leaks, fuel pressure and overheating.
what were the other numbers?
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Car: 1988 GTA
Engine: 5.0 TPI
Transmission: T5
Axle/Gears: 9 Bolt, 3.45
Re: Failed emissions, nox is crazy high
Here's the full printout. The HC was a little high, but that's probably due to my ford 19# injectors. I can fix that with a tune. Also, the gas cap failed, but that's easily replaceable.
#6
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Re: Failed emissions, nox is crazy high
prolly for a start-tee in a vac gauge to the egr valve line that you can run to the windshield and watch as you drive around to verify if you are getting any vacuum (pwm) to the egr valve. i agree-wow for the nox number. if vacuum is being applied-check your egr valve at idle with manual vacuum-it should make the motor stumble. check timing. retard as required. you may need a cat.
#7
Re: Failed emissions, nox is crazy high
prolly for a start-tee in a vac gauge to the egr valve line that you can run to the windshield and watch as you drive around to verify if you are getting any vacuum (pwm) to the egr valve. i agree-wow for the nox number. if vacuum is being applied-check your egr valve at idle with manual vacuum-it should make the motor stumble. check timing. retard as required. you may need a cat.
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