Usually if your oxygen sensor is bad you will thorow a code for it right? Well the only code i am throwing is for my EGR. My car is running really rich. So rich that sometimes when i first start driving it sounds i like my rev limiter is at 3,000 rpms at mid throttle.It kills so much performance from my engine. I want to make sure its my oxygen sensor thats wrong before i go and spend a hundred bucks on an oxygen sensor. But from what i have read so far that about the only to find out if you aren't throwing a code. If someone could hook me up with some answers that would be greatly appreciated.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by DropSquadCivic &raquo;</TD></TR><TR><TD CLASS="quote">Usually if your oxygen sensor is bad you will thorow a code for it right? </TD></TR></TABLE>
Not necessarily an O2 sensor can become "lazy" which means it is still functioning without a check engine light, but reacting very slowly to air/fuel changes.

What is your fuel pressure at? and what ECU and injectors are you using?

 

theres a way to test the o2 sensor with a voltmeter or something like that..

 

I think i'm running on 42psi and i have my stock p13 ECU, with stock injectors.

 

Does your map sensor have the o-ring still. I know that if the o-ring is missing it will cause the map to read the wrong vacuum and create a rich environment and will cause the problem you are describing.......

 

My map sensor is mounted on the firewall, and there's a male end on it and it connects to my vaccum line. I know what you are talking about though because my map sensor messed up, what's happening with my car now is a lighter version of that. Maybe driving my car with the map sensor messed up for a while might have messed the oxygen sensor.

 

bump

 

it happened to me once
i replaced my O2 sensor and my woes went away

 

To check your o2 sensor's reaction time you would need an osciliscope. I think a good sensor reacts in about 2 miliseconds(could be wrong). So there is no way you could check it with a voltmeter.

Good Luck
-Proper