ok about two months ago i had a high flow cat and full exhasut put on my 2000 civic si. the engine light came on, so i did the jumper thing and got the code... its number 67, which was Catalyst System Efficiency Below Threshold , i reset my ecu twice by taking out the back up radio fuse, and it went out for a couple hours and then came back on. how do you get it to stay off and how long do you have to wait before it would accept the mod?

 

get a chipped ecu that will erase o2 sensor

 

It wont accept the mod. The cat you put on is apparently not efficient enough to satisfy the o2 sensor.

 

i was reading somewhere before to get a o2 simulator or sumthing.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by robert_v &raquo;</TD></TR><TR><TD CLASS="quote">get a chipped ecu that will erase o2 sensor</TD></TR></TABLE>

please don't listen to this, your o2 is one of your most important sensors. O2 sims work well as secondary o2's, and could solve your problem. What kind of high-flow cat did you buy?

 

did you feel the the difference with a high flow cat

 

try using your stock cat again. if check light still comes on then its your o2 but if it dies then its your high flow cat that is causing the problem