kurrupt626

Car: 1997 Honda Civic DX
Mileage: 110,000

First post here I just got my car smogged and it failed. I took it earlier this month and it failed, so just recently I took it to some guy and had the exhaust manifold changed and the o2 sensor replaced. About $450 put into fixing it and it just failed again. The numbers read:
Overall Test Results:
Visual Inspection: Pass
Functional Check: Fail
Emissions Test: Fail
"No match has been found or test preformed off-line. The consumer is responsible for retaining the VIR for reference throughout the vehicle registration process." I think this was because I just got it fixed?

Also it said:
"This vehicle failed the MIL/Check Engine Light due to failure to successfully complete all OBD self tests." I have no idea about this one either.

ASM Emission Test Results:
Test: 15mph
RPM: 1954
%CO2 Meas: 14.7
%O2 Meas: 0.0
HC (PPM): max-66, ave-9, meas-13
CO(%): max-0.57, ave-0.02, meas-0.24
NO (PPM): max-487, ave-57, meas-595 <----
Fail

Test: 25mph
RPM: 1893
%CO2 Meas: 14.5
%O2 Meas: 0.0
HC (PPM): max-49, ave-7, meas-15
CO(%): max-0.55, ave-0.03, meas-0.44
NO (PPM): max-774, ave-136, meas-666
Pass

So as far as I can tell, it failed the nitric oxide test by ~100 points. So if I could lower that somehow it would pass right? I heard that I could use premium gas or change spark plugs/air filter... does any of that have any help with the nitric oxide? Thanks!

rugimpy

Catalytic converter helps.

kurrupt626

I thought the exhaust manifold came with the catalytic converter? Like it was 1 single piece?

kurrupt626

I read that 'retarding the timing' can help a bit. Can anybody vouch for this?