will a bad o2 sensor cause a high nox level on smog? i failed twice with a b20. i got a 3500 nox level and 700 is max. also, my check engine light comes on every once in a while, could that be cause by an o2? i know that a bad o2 will turn it on but only every once in a while?!?!

 

a bad o2 sencor will not cause excessive nox levels

 

why don't you check the code and find out?

 

check the forced induction section, there was this guy who only changed the o2 after he failed. hc, co, and nox went down

 

checked my codes. bad o2. and fuel supply system (injectors and maybe filter). i changed my filter like 30k ago. think it's still good?

 

check your catalic convertor. it might be bad

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by GoCarInteg &raquo;</TD></TR><TR><TD CLASS="quote">i changed my filter like 30k ago. think it's still good?</TD></TR></TABLE>

I think its supposed to be changed every 60k miles. So that should be fine.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by TEiK &raquo;</TD></TR><TR><TD CLASS="quote">check your catalic convertor. it might be bad</TD></TR></TABLE>

i thought the same thing. i just replaced the cat and it only dropped the nox about 200. oh well.. hollowed out my old one

 

Have you check your timimg (TDC mark)?

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by GoCarInteg &raquo;</TD></TR><TR><TD CLASS="quote">checked my codes. bad o2.
</TD></TR></TABLE>
you might have a lazy o2, replace it.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by TEiK &raquo;</TD></TR><TR><TD CLASS="quote">Have you check your timimg (TDC mark)?


you might have a lazy o2, replace it.</TD></TR></TABLE>

i was on 16. but i replaced my o2. **** was white. $35 at the junkyard. passed with flying colors... thanks everybody

 

good that its fixed. was the car still on OBD1 or was it 2 after the swap?
on OBD2 cars, if you have a check engine light on you always fail emissions, regardless of what it is.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by P95 &raquo;</TD></TR><TR><TD CLASS="quote">good that its fixed. was the car still on OBD1 or was it 2 after the swap?
on OBD2 cars, if you have a check engine light on you always fail emissions, regardless of what it is.</TD></TR></TABLE>


still kept it OBD1. The check engine light kept coming on at random. The wierd thing is that i brought my **** to honda so they could read the light and nothing showed up on their system. oh well.