I had a CEL a couple of months ago, and it went away before I could take it in to get checked out. I don't think it actually reset the computer becuase weeks later when I took it in for something else they told me that the code number was still in there. It was from the secondary O2 sensor in my cat (67). A few weeks later it showed up again on my trip to the H-T meet in Nashville. I didn't worry about it because I was replacing the cat in a couple of days anyway. Now I have my new exhaust on with the sensor wrapped in aluminum foil and taped up out of the way. Several people here claim that that will keep it from throwing the CEL. The problem is that it never went away this time. Why did it go away the first time, and should it do the same thing this time?

 

two easy ways to do it:
1 - pull off the negative battery terminal, wait five mins or so, and put back on
2 - pull the 15 amp fuse in the top left corner of the underhood fusebox - wait five mins, put back in (my favorite method)

edit: not sure about your o2 sensor problem...

 

Thanks. Will this actually rest the computer or just get the light to go away?

 

supposed to reset the ecu....just follow the steps above

I choose to diconnect negative terminal most of the time

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by py1188 &raquo;</TD></TR><TR><TD CLASS="quote">supposed to reset the ecu....just follow the steps above

I choose to diconnect negative terminal most of the time</TD></TR></TABLE>

But then you have to reprogram all your radio stations again.

 

stock radio make sure you have teh code

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by acuracing &raquo;</TD></TR><TR><TD CLASS="quote">

But then you have to reprogram all your radio stations again. </TD></TR></TABLE>

Yeah that is always a bitch. Number 2 is the best

 

....thats why you put a wire to your bat from your deck and always on ....just take the faceplate off when not inuse

 

If I remember correctly there is a backup fuse as well that needs to be removed besides just the 15 amp.

Regardless, theres no need to wait five minutes, the reset is almost instantaneous.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 1GreyTeg &raquo;</TD></TR><TR><TD CLASS="quote">If I remember correctly there is a backup fuse as well that needs to be removed besides just the 15 amp.

Regardless, theres no need to wait five minutes, the reset is almost instantaneous. </TD></TR></TABLE>

I tried pulling the ECU fuse and I waited atleast 10 mins and nothing happend. Had to pull battery, but I pulled the positive.

 

Code 67 means you catalyst efficiency is below threshold. I.e. the primary and secondary O2 sensor are reading pretty much the same meaning the catalytic converter is not doing it's job. The code is 3 trip logic meaning it must see the catalyst inefficiency in 3 consecutive trips before setting the CEL... if you have 1 trip where it does not see the inefficiency it will turn off the light. If you scan the ECU it will have a section where the code is pending.

Get rid of that test pipe and get a high flow cat.

 

In some cases a new High-flow cat will still thrpw the code 67. I have a brand new Carsound along with a new O2 sensor, still throwing a code 67

 

If you have pryometer or infared thermometer you can easily check the cat to see if it's working. The outlet temp should be approximately 100deg celcius higher than the inlet temp. If it's not then most likely you have a bum cat.

 

yeah...when my cel comes on i use a snap-on scan tool to reset and read my comp. (perks of working at a full service repair shop where the mechanics have a **** load of cool *** toys. )