Cat/Header
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From: East Windsor, Ct, Usa
Cat/Header
In my 98 civic coupe.. my cat is where most headers are in the front of the engine.. if i removed the cat and bought a cheap ebay header.. would this make any difference.. as in gas mileage wise , hp wise or just for loooks .. also would that set off a engine light due to o2 sensor or would it read the same with the o2 sensor on the header.. thanks
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Re: Cat/Header (Chillmatic)
You might see a slight increase on the butt-dyno. It will set off a CEL because the second o2 sensor, but it won't affect performance. The second o2 only checks to see if the cat is working.
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Re: Cat/Header (Chillmatic)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Chillmatic »</TD></TR><TR><TD CLASS="quote">In my 98 civic coupe.. my cat is where most headers are in the front of the engine.. if i removed the cat and bought a cheap ebay header.. would this make any difference.. as in gas mileage wise , hp wise or just for loooks .. also would that set off a engine light due to o2 sensor or would it read the same with the o2 sensor on the header.. thanks</TD></TR></TABLE>
It's not going to make much more power than stock. It's really not worth taking the cat off for street use(for any amount of HP, IMO). It will set off your check engine light. Your secondary 02 will have nowhere to go..or it will just go in the raw, uncatalyzed exhaust stream. Since the secondary O2 is a monitor to see if the cat is working or present...there will be a CEL.
You could buy an entire EX setup. That would definately keep you legal. The 96-00 EX header is nice. You will need to find the EX cat. An EX header can be found on ebay for cheap a lot of the times.
If you choose to buy a cheapo EBAY header, then either buy an EX or Si cat. If you buy an OBD2 cat, you can bolt in the secondary O2 sensor and you'll only have to lengthen the wires. If you buy an OBD1 (92-95 civic) cat, you will have to weld on a secondary O2 bung somewhere after the cat. Same with an OBD0 cat.
You can also get a high flow cat. MAKE SURE IT'S A CAT AND NOT JUST A TESTPIPE LABELED "HIGH FLOW CAT". Theres's scammers on ebay that sell "high flow cats" that are just hollow pipes with no catalyst.
Padawan (a mod on here) says good things about SMSP high flow cats. But apparently, they're not cheap. A cheap high flow cat will MOST LIKELY set off your check engine light as the catalyst is not very efficient.
Again, either way you go, you wont see a ton of power come out of it. However, if you do a combination of the header, the cat, an exhaust, an intake, an intake manifold from a 96-00 EX (automatic so your ECU can still run the IACV), you will see some decent power gains. However...with that amount of money, you could just buy a D16Y8 swap if you can find one. That would net around 20more HP right off the bat..and the Y8 responds much easier to mods than the Y7.
It's not going to make much more power than stock. It's really not worth taking the cat off for street use(for any amount of HP, IMO). It will set off your check engine light. Your secondary 02 will have nowhere to go..or it will just go in the raw, uncatalyzed exhaust stream. Since the secondary O2 is a monitor to see if the cat is working or present...there will be a CEL.
You could buy an entire EX setup. That would definately keep you legal. The 96-00 EX header is nice. You will need to find the EX cat. An EX header can be found on ebay for cheap a lot of the times.
If you choose to buy a cheapo EBAY header, then either buy an EX or Si cat. If you buy an OBD2 cat, you can bolt in the secondary O2 sensor and you'll only have to lengthen the wires. If you buy an OBD1 (92-95 civic) cat, you will have to weld on a secondary O2 bung somewhere after the cat. Same with an OBD0 cat.
You can also get a high flow cat. MAKE SURE IT'S A CAT AND NOT JUST A TESTPIPE LABELED "HIGH FLOW CAT". Theres's scammers on ebay that sell "high flow cats" that are just hollow pipes with no catalyst.
Padawan (a mod on here) says good things about SMSP high flow cats. But apparently, they're not cheap. A cheap high flow cat will MOST LIKELY set off your check engine light as the catalyst is not very efficient.
Again, either way you go, you wont see a ton of power come out of it. However, if you do a combination of the header, the cat, an exhaust, an intake, an intake manifold from a 96-00 EX (automatic so your ECU can still run the IACV), you will see some decent power gains. However...with that amount of money, you could just buy a D16Y8 swap if you can find one. That would net around 20more HP right off the bat..and the Y8 responds much easier to mods than the Y7.
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Jan 18, 2005 09:36 AM