What's up everyone?? Iv come to hondaTech cause I'm at a loss. I have a 93 Eg hatch with a d15b7 in it. Time for emmsions came up an it failed.
So I did a tune up. Replaced cat, plugs, Iac to fix my funny idle issue, an check an set timing dead on.

Issue I'm having now the car fails nox by 4 points every time. Limit I'm az is 2.50 I keep getting 2.54

I pass the other 2 parts with flying colors...
Iv done a lot of searching an found some ways to sneak by an they still failed ( retard timing) failed
(Guarantee pass) failed

I took the car to a local shop because im out of ideas. They couldn't figure it out. Iv changed everything but the o2, plug wires, fuel filter an pump.

Any help would be really helpful. I just want to pass this bad boy so I can install my LSVtec.

 

I also ran sea foam. Fresh oil change and bought a new thermostat.

 

Your combustion is too hot, which is because you're burning too lean.
Either your injectors are dirty or not opening, your fuel pump or filter is failing, your water pump or radiator is not circulating, or your O2 sensor/wiring is faulty.
Since this is a 93, the O2 should be changed regardless, and the fuel filter should also be considered.
My money is on your O2.

 

I bought a o2 sensor this morning. Taking the car back tomorrow morning. Thanks for your suggestions

 

O2 that was on the car looked like it went through hell an back. A lot of build up an really white

 

Car passed with flying colors.
New o2