I went through NJ State inspection today and failed for emissions on my 87' 535is w/ 220,900 miles. The following are the readings from the print out provided.
GAS Standard Reading
NOx 1110 2262
HC 148 59
CO% 0.83 0.04
CO2% 14.2
o2% 0.5
RPM 0
I also should tell you that I disconected the O2 sensor due to problems in the rain. Could this have caused the high NOx reading?
Any advice before I just run the car through with the O2 sensor attached?
TIA
George
Emissions Failure E28
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ben89325is
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George - sorry to hear that!
High NOx reading is most likely indicative of a lean condition typically caused by an intake vacuum leak. The unplugged O2 sensor could be contributing to the high NOx reading. I would reconnect it prior to re-testing.
I would check all of the intake plumbing and vacuum hoses to make sure nothing is unplugged, cracked, hard or otherwise leaking. Leaking intake manifold gaskets will cause this also. Does the car idle smoothly? Rough idle sometimes indicates an intake leak also.
A non-function catalytic converter could also cause NOx to be high.
For comparison, here are my results from 11/14/06 from the '84 533i at 96k miles:
GAS - STANDARD - READING
NOx - 1110 - 800
HC - 148 - 9
CO% - 0.83 - 0.21
CO2% - NA - 14.5
O2% - NA - 0.1
These results are particularly good. The rubber intake plumbing on the 533 was so bad that most of the hoses and vacuum lines cracked and fell apart while being removed and the car would not idle smoothly, sometimes at all. All of it was replaced prior to attempting inspection.
Call me tomorrow if you get a chance...
Mark
High NOx reading is most likely indicative of a lean condition typically caused by an intake vacuum leak. The unplugged O2 sensor could be contributing to the high NOx reading. I would reconnect it prior to re-testing.
I would check all of the intake plumbing and vacuum hoses to make sure nothing is unplugged, cracked, hard or otherwise leaking. Leaking intake manifold gaskets will cause this also. Does the car idle smoothly? Rough idle sometimes indicates an intake leak also.
A non-function catalytic converter could also cause NOx to be high.
For comparison, here are my results from 11/14/06 from the '84 533i at 96k miles:
GAS - STANDARD - READING
NOx - 1110 - 800
HC - 148 - 9
CO% - 0.83 - 0.21
CO2% - NA - 14.5
O2% - NA - 0.1
These results are particularly good. The rubber intake plumbing on the 533 was so bad that most of the hoses and vacuum lines cracked and fell apart while being removed and the car would not idle smoothly, sometimes at all. All of it was replaced prior to attempting inspection.
Call me tomorrow if you get a chance...
Mark