Well, I got a CEL while cruising on the freeway. I did the thing to pull codes and got I suppose a 67

I mean suppose because it's hard to keep track and I thought I had a 76 or 77 but there is no 76 or 77 so it must be 67 which is:

Catalyst system Efficiency Below Threshold malfunctioning or defective catalyst system

Which is what I got from this site: http://www.c-speedracing.com/faq/05.php

Which seems right since I changed my cat to a high-flo cat so now I'm wondering, how do I bypass this? I know there's something you can make that you just wire on the O2 sensor. I haven't done a search for it yet or anything. But I'm sure there's a DIY for it?

Thanks.

 

saying CEL light is like saying ATM machine. [/petpeve]

 

(SP)


PEEVE

[/petpeeve]

 

or NT Technology

 

aside from the peeving going on up there.... to answer your question, the high flow cat (unless it's the style that is basically just a pipe with cat material on the outside of it) should get rid of enough of the exhaust gases to cause the O2 to see a lower reading than the front one. Thus causing no CEL.
I'd bet you have one of the Ebay specials on there, they will cause this problem. Either get yourself a better quality high flow cat or pick up an O2 simulator that will bypass your second O2 and make the ECU think everything is fine.
there is also a chance with you messing around under there you disconnected the second O2 and forgot to reconnect it or taking it out and putting it back in messed it up.

 

Well, basically it's a cat-eliminator... and a shop installed it (under the table) for me, so I'm sure the o2 was hooked up fine. And it did run fine for about 2 weeks, then it came on..

Can I buy the o2 simulator somewhere online? Or isn't there a DIY somewhere? I know you can just hook up certain resistors and such :dunno:

Thanks for the help.

 

well a high flo cat and a test pipe are two completely different things.

Just having a pipe WILL cause that light to go on, as it is throwing out way more hydrocarbons then it usually did. Anyway I don't know of a bypass, maybe someone else can help you with that.

 

O2 simulator

 

Thank you :bowdown:

 

if you don't want to build your own

try
www.o2sensorsimulator.com
or
http://www.highrevmotorsports.com/ca...3c799dabda55bf