car won't pass smog!

[tAngo.]

Took my car to get smoged and did not pass the first time due to a functionality test it had an evap leak. So I fixed it and took it for the second time and pass in that category but now it won't pass cause the NOX is to high so idk if it's a o2 sensor or a exhaust leak. Any ideas?

[Cabriolet]

high nox means air leak. you arent passing the evap test bc the same issue. have the car smoke tested. most likely you will also need a new cat, you will gain power by dumping your old one.

[tAngo.]

high nox means air leak. you arent passing the evap test bc the same issue. have the car smoke tested. most likely you will also need a new cat, you will gain power by dumping your old one.

They did a smoke test and the charcoal canister was bad.
So now there saying it my have a exhaust leak or the o2 is bad
But I'm not sure what it is now

[jlevie]

A bad O2 sensor usually causes the engine to run rich. High NOX is from an engine that is running lean, which could be from intake leaks, dirty injectors, bad AFM, etc. The first action should be to smoke test the engine to look for intake leaks. If an oil smoke pressure of 2-4psi can be held for at least 5 minutes, there are no leaks.

The other cause of high NOX, even when the engine is running right is a bad catalytic converter.

BTW: the O2 sensor is a scheduled maintenance item with a replacement interval of 100k.

[tAngo.]

A bad O2 sensor usually causes the engine to run rich. High NOX is from an engine that is running lean, which could be from intake leaks, dirty injectors, bad AFM, etc. The first action should be to smoke test the engine to look for intake leaks. If an oil smoke pressure of 2-4psi can be held for at least 5 minutes, there are no leaks.

The other cause of high NOX, even when the engine is running right is a bad catalytic converter.

BTW: the O2 sensor is a scheduled maintenance item with a replacement interval of 100k.

Oh ok that sounds more likely then what the smog guy was telling. I'll start looking into that then.
how could I test the injectors to see if they're dirty?

[tAngo.]

:nice:
Well car pass smog

[mymonkey562]

I had the same issue my nox reading was about 2200 passes after I cleaned the injectors

[not_a_kiwi]

Out of curiosity where might one get a smoke test done?

[iceman44]

I had the same probelm i cleaned the maf sensor change o2 sensor and made sure my plugs were gap right after that i reset computer than let it run for 20 min so it can reset itself

[not_a_kiwi]

How do you reset the computer?