acme

I failed my inspection beacause the ecu is reading my catalytic converter as bad. I have headers and exhaust. Is this happeneing becsuae the o2 is in the wrong place. I have two on the headers, ones neare the bottom and one is closer to the top. help.

redman223

Is the cat stock? I always read things on h-t about carsound cats going bad really soon, the only good thing about them is that they are cheap, so just buy a new one right before you get inspected again.

delScho

You said both of your O2s are on the header? The secondary one wants to sniff after the cat to see if it's working or not. If you put it on before the cat, it'll think your TWC is toast. Put the O2 in the right place and see if your code changes.

bloodhound

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by delScho &raquo;</TD></TR><TR><TD CLASS="quote">You said both of your O2s are on the header? The secondary one wants to sniff after the cat to see if it's working or not. If you put it on before the cat, it'll think your TWC is toast. Put the O2 in the right place and see if your code changes. </TD></TR></TABLE>

No, they are both supposed to be on the header. How old is your cat? Is it going bad?

Also, what car?

delScho

Is it one of the ones where the cat is integrated into the exhaust manifold?

stockegsix

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by acme &raquo;</TD></TR><TR><TD CLASS="quote">I failed my inspection beacause the ecu is reading my catalytic converter as bad. I have headers and exhaust. Is this happeneing becsuae the o2 is in the wrong place. I have two on the headers, ones neare the bottom and one is closer to the top. help.</TD></TR></TABLE>


take off one header, civics only use one header. J/k

is your car a DX? was the stock cat with the stock header? why not put the stock parts back on just for emission testing/

acme

My car is a 97 Civic HX. First i got the cat back exhaust then i got the headers installed then the high flow cat. all from lous custum exhaust. I got all of thise done around a month ago. My cat is not going back the computer just thinks it is. The guy at lous had one suggestion, to get an extention for the o2 sensor and put it below the header instead of up top. I cant put the stock parts back on because i dont have them, Does anyone have any suggestions?

Relic1

for the ECU to read a good working cat it needs to have one O2 in front of the cat(primary), and one O2 in behind the cat (secondary). if you have both mounted in front of the cat it will see no difference in the readings and set the code.

delScho

However you tricked the ecu is the problem then. Check all the wiring and make sure it's doing its job. If you're running a cheater, placement isn't an issue. Strange how it would read inefficient catalyst and not a sensor failure. Weird.