installing a dc jdm 4-1, carsound high flow cat and Greddy evo exhaust on 99-00 Civic Si soon. will it throw a code for o2 sensor or the catalyst system? anyone have any experience with this? any way of getting around the CEL other than going to an OBD-1 computer?

thank you for any help at all

-Graham

 

it could possibly throw a code, since a really high flow cat won't change much between O2 sensors. a lot of people use an O2 simulator. let me know if you need one. I'll let you know tomorrow how much, since my friend has a few at his shop

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Downey &raquo;</TD></TR><TR><TD CLASS="quote">installing a dc jdm 4-1, carsound high flow cat and Greddy evo exhaust on 99-00 Civic Si soon. will it throw a code for o2 sensor or the catalyst system? anyone have any experience with this? any way of getting around the CEL other than going to an OBD-1 computer?

thank you for any help at all

-Graham
</TD></TR></TABLE>

No, it won't toss a code. Never did on my 99 Si and I ran a similar setup. The only time when I got the CEL was when I put in the test pipe with the turbo kit. That took about 3 days before the light came on. As far as getting rid of it, use an O2 simulator.

 

thanks alot for the quick response guys!

 

It'll throw a code if you don't have the O2 conencted to the converter (not all come with an O2 bung) or a simulator.

 

my friend had one on his si and it threw a code. I am getting the code from my testpipe and it comes on very very frequently. Thank god I'm going obd1 soon.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by SOHC_MShue &raquo;</TD></TR><TR><TD CLASS="quote">my friend had one on his si and it threw a code. I am getting the code from my testpipe and it comes on very very frequently. Thank god I'm going obd1 soon. </TD></TR></TABLE>

There is no question that a test pipe WILL throw a code on an OBD-II vehicle. He was asking about a high flow cat, which should not be throwing any codes.

 

if you install a DC header it will also throw a code

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by FlamencoEsi &raquo;</TD></TR><TR><TD CLASS="quote">if you install a DC header it will also throw a code </TD></TR></TABLE>

Incorrect. Ran a DC 4-1 on my Si for quite some time with 0 problems. There is NO reason a code should come from a carb legal header, much less ANY header that retains the O2 bung.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Hybrid93Eg &raquo;</TD></TR><TR><TD CLASS="quote">

There is no question that a test pipe WILL throw a code on an OBD-II vehicle. He was asking about a high flow cat, which should not be throwing any codes.</TD></TR></TABLE>

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by SOHC_MShue &raquo;</TD></TR><TR><TD CLASS="quote">my friend had one on his si and it threw a code. I am getting the code from my testpipe and it comes on very very frequently. Thank god I'm going obd1 soon. </TD></TR></TABLE>

i said that my friend had a hi-flow on his si and it threw a code .

 

with a simulator in place...will the car run normal or will something like the a/f still be off without a real sensor in the exhaust stream adjusting everything? i have been running for some time with no secondary hooked up and i would LOVE to see that cel go away.

 

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

i said that my friend had a hi-flow on his si and it threw a code . </TD></TR></TABLE>

Saying your friend had "one" was not too clear, so I am sorry for reading it incorrectly. There was talk of both test pipes and high flows, so "one" was not exactly specific.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 2000CX &raquo;</TD></TR><TR><TD CLASS="quote">with a simulator in place...will the car run normal or will something like the a/f still be off without a real sensor in the exhaust stream adjusting everything? i have been running for some time with no secondary hooked up and i would LOVE to see that cel go away.</TD></TR></TABLE>


As far as I know, it will run just like normal. I have not personally had any experience with these products myself, so I cannot gaurantee it.

 

hey Downey what happened to your hatch?

 

probably need an o2 stimulator.... i did this on a friend's ex and that fixed the prob.

 

lets see... my experienses:

96 civic with carsound high flow cat.. --&gt; no codes
96 civic with no cat but 02 still hooked to the harness --&gt; no codes

as soon as i disconect teh 02 from the wire harness then it throws a code.

maybe my car is special? nahhhh

 

the sole purpose of the second O2 sensor in the cat of obd2 cars is to test that the cat is doing its job and leaning out the mixture within a certain range.

so... if your high flow cat sucks and doesnt do its job within set parameters you will get an O2 sensor code.

i have not had any CELs with my high flow carsound cat on my obd2 civic.

 

i ran an identical (i ran the OEM rather than the DC) setup on my car and never had a CEL of any sort occur.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Hybrid93Eg &raquo;</TD></TR><TR><TD CLASS="quote">

Incorrect. Ran a DC 4-1 on my Si for quite some time with 0 problems. There is NO reason a code should come from a carb legal header, much less ANY header that retains the O2 bung.</TD></TR></TABLE>

i believe he was asking about the dc jdm header which isn't carb legal, not the usdm version

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by FlamencoEsi &raquo;</TD></TR><TR><TD CLASS="quote">if you install a DC header it will also throw a code </TD></TR></TABLE>

I've got a DC 4-2-1 on my SI and I've never thrown a code due to it.

 

Random Tech cat throws a code on my Si. CODE 67...for the last 30,000 miles. I think i'm going to get a carsound. When I put a stock cat in, the code resets.

 

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

I've got a DC 4-2-1 on my SI and I've never thrown a code due to it.</TD></TR></TABLE>

thats weird i wonder why mine gave me a code???? i have stock everything exept a dc header...

 

So which high flow cats are you guys using that does not through a CEL on an OBDII? I have a 00 GSR and am interested in getting a high flow cat.