Test pipe to eliminate cat - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

11-26-2001, 09:23 AM

can I get I pipe to replace my cat, but where i can put my cat back on if I move out to cali.  I'm in Oklahoma so I could get away with it.  Also how much hp might I gain with a pipe if I have catback exhuast?  Any ideas?  i know that's sort of a broad dumb question..so where can I order a testpipe?

Chance

whateverjames · 11-26-2001, 09:42 AM

i think www.pdm-racing.com has them

http://www.pdm-racing.com/products/pdmdump.html

11-26-2001, 09:49 AM

It said this.  Is this true?

NOTE ** S14 240SX owners ** (1995-1998) PDM does NOT offer a dump pipe for the S14, as the catalytic converter is located just below your exhaust manifold. S14's are OBDII, and require the use of a catalytic converter to monitor and maintain your engine's mixture. Removal of the cat will cause computer errors.

*DSC* · 11-26-2001, 10:54 AM

yes. From what i've heard you can get your ecu reprogramed so you can put a pipe on their but I dono who, if anybody sells them for an s14. If your set on doing it you might have to get it custom made.

11-26-2001, 02:49 PM

shucks....stupid tree huggers.

Impact · 11-26-2001, 03:46 PM

Hey man.......not all of us hug trees..

vancouvers14 · 11-26-2001, 06:27 PM

just hollow the cat out.  you don't need to replace it

yenpit · 11-26-2001, 06:54 PM

i think krunko is right. i dont have my car here, but if you have two O2 sensors (one ahead of, one behind cat) u'll prob trip the ECU/check engine light. not sure why this happens but figure the SECOND sensor reads within certain parameters AFTER the cat. when u change the "flow" with a pipe or punchin ur cat out it will often trip the ECU code. this happens on late OBD II hondas (ie 99-00 civic si). have u considered a hi flow cat like Magnaflow...?? u can build a pipe and replace the cat, then if it does trip the ECU put the cat back in.
if u do this im sure we'd all like to know what happens... let us know!!

11-26-2001, 10:08 PM

well how much HP are youg oing to see with a highflow cat?  I would think it wouldn't be anywhere near just putting in a pipe, but I wouldnt' want to put in a pipe if its going to screw up my car and make me ECU light go on.

yenpit · 11-27-2001, 08:31 AM

late model cats are MUCH more technically advanced than 8-10yrs++ ago. they are restrictive but i would guess u'd only loose a few HP (unless urs has high miles on it cuz they do clog up!). other drawback is noise....cats quiet exhaust. if u punch or replace with pipe ur car WILL get louder, unless thats what u want.
these new hi-flow cats are less restrictive than OEM, and u can see a "few" HP gain over OEM. ya gotta weigh all this stuff!
hasnt anyone actually done this on a late 240..?? krunko, i speak from other import experience (this is my first 240, and its not on the road yet!) but most ive exp are 4cyl FI cars....very similar.
guess...remove or punch out=5-7 HP + noise, possible ECU prob. hi-flow cat=3-5 HP + legal, little chance of ECU prob.

*nismo270r* · 11-27-2001, 08:45 AM

Yes there is an O2 sensor in the real catalytic convertor on an S14.  The one that is where a catback exhaust system hooks up to is not a real cat, rather just one there for looks I guess.  I've heard it was put in for visual emissions inspections, but that could just be rumor.  Either way, the fake cat has nothing much in it at all anyways.  You're real cat is right off the header, and has an O2 sensor.  So you either have to get a Random Tech cat (I don't know the part #), or just get a Hotshot header (full header, unlike Greddy SS short header) and replace the fake cat with a real universal RT, or Carsound cat or something.  That's if you're worried about emissions.  It'd probably sound better with a cat on there too.  But if you don't want to, just weld a pipe in where your fake cat is with the Hotshot header and that's the freeist flowing exhaust you can get.

11-27-2001, 09:05 AM

what kind of problems with the ECU w0uld you experience without the cat...isn't there a possibility it could make your car run worse/slower?

vancouvers14 · 11-27-2001, 11:19 AM

well, the other issue is legality.  running no cat is illegal in most places.  plus, if you have a catback, it will get obscenely loud.  i set off probably one car alarm a week, with my exhaust.  i couldn't imagine it getting louder

HippoSleek · 11-27-2001, 12:24 PM

I agree that removal of the cat will lead to a CEL/code.  Yes, this will cause you engine to go into a "safe mode" which will make it run like dookie.  I also 100% agree with yenpit's statement that the science of cats has improved so that you are not going to see huge gains by removing it or upgrading to a high-flow unit.  Some - but not huge.  If you are making huge power or using an engine/header that is not designed to have a cat that may be another story - but for basic bolt ons, I've not seen straight pipes give huge gains like people would like to believe.

The cons are sound and pollution.  I'm no tree hugger, but having my car smell like a '71 Catalina is not high on my list of mods <img src="http://www.zilvia.net/f/iB_html/non-cgi/emoticons/wink.gif" border="0" valign="absmiddle" alt=';)'>  For the money, I think there are other mods that would give you more power with fewer drawbacks.

BTW: after having this debate about 16 times, I believe that most '95s are OBD I with a single, pre-cat o2.

11-26-2001, 09:23 AM	#1
Guest Posts: n/a	can I get I pipe to replace my cat, but where i can put my cat back on if I move out to cali.  I'm in Oklahoma so I could get away with it.  Also how much hp might I gain with a pipe if I have catback exhuast?  Any ideas?  i know that's sort of a broad dumb question..so where can I order a testpipe? Chance

11-26-2001, 09:42 AM	#2
whateverjames Nissanaholic! Join Date: Jul 2001 Location: St. Louis Age: 45 Posts: 2,263 Trader Rating: (0) Feedback Score: 0 reviews	i think www.pdm-racing.com has them http://www.pdm-racing.com/products/pdmdump.html

11-26-2001, 09:49 AM	#3
Guest Posts: n/a	It said this.  Is this true? NOTE S14 240SX owners (1995-1998) PDM does NOT offer a dump pipe for the S14, as the catalytic converter is located just below your exhaust manifold. S14's are OBDII, and require the use of a catalytic converter to monitor and maintain your engine's mixture. Removal of the cat will cause computer errors.

11-26-2001, 10:54 AM	#4
DSC New Title Join Date: Aug 2001 Location: VA Posts: 3,454 Trader Rating: (0) Feedback Score: 0 reviews	yes. From what i've heard you can get your ecu reprogramed so you can put a pipe on their but I dono who, if anybody sells them for an s14. If your set on doing it you might have to get it custom made.

11-26-2001, 02:49 PM	#5
Guest Posts: n/a	shucks....stupid tree huggers.

11-26-2001, 03:46 PM	#6
Impact Leaky Injector Join Date: Oct 2001 Posts: 125 Trader Rating: (0) Feedback Score: 0 reviews	Hey man.......not all of us hug trees..

11-26-2001, 06:27 PM	#7
vancouvers14 Zilvia Addict Join Date: Jul 2001 Posts: 868 Trader Rating: (0) Feedback Score: 0 reviews	just hollow the cat out.  you don't need to replace it

11-26-2001, 06:54 PM	#8
yenpit Zilvia Addict Join Date: Sep 2001 Location: Holland Michigan Posts: 798 Trader Rating: (0) Feedback Score: 0 reviews	i think krunko is right. i dont have my car here, but if you have two O2 sensors (one ahead of, one behind cat) u'll prob trip the ECU/check engine light. not sure why this happens but figure the SECOND sensor reads within certain parameters AFTER the cat. when u change the "flow" with a pipe or punchin ur cat out it will often trip the ECU code. this happens on late OBD II hondas (ie 99-00 civic si). have u considered a hi flow cat like Magnaflow...?? u can build a pipe and replace the cat, then if it does trip the ECU put the cat back in. if u do this im sure we'd all like to know what happens... let us know!!

11-26-2001, 10:08 PM	#9
Guest Posts: n/a	well how much HP are youg oing to see with a highflow cat?  I would think it wouldn't be anywhere near just putting in a pipe, but I wouldnt' want to put in a pipe if its going to screw up my car and make me ECU light go on.

11-27-2001, 08:31 AM	#10
yenpit Zilvia Addict Join Date: Sep 2001 Location: Holland Michigan Posts: 798 Trader Rating: (0) Feedback Score: 0 reviews	late model cats are MUCH more technically advanced than 8-10yrs++ ago. they are restrictive but i would guess u'd only loose a few HP (unless urs has high miles on it cuz they do clog up!). other drawback is noise....cats quiet exhaust. if u punch or replace with pipe ur car WILL get louder, unless thats what u want. these new hi-flow cats are less restrictive than OEM, and u can see a "few" HP gain over OEM. ya gotta weigh all this stuff! hasnt anyone actually done this on a late 240..?? krunko, i speak from other import experience (this is my first 240, and its not on the road yet!) but most ive exp are 4cyl FI cars....very similar. guess...remove or punch out=5-7 HP + noise, possible ECU prob. hi-flow cat=3-5 HP + legal, little chance of ECU prob.

11-27-2001, 08:45 AM	#11
nismo270r Premium Member Join Date: Oct 2001 Location: Lafayette, IN Age: 45 Posts: 715 Trader Rating: (0) Feedback Score: 0 reviews	Yes there is an O2 sensor in the real catalytic convertor on an S14.  The one that is where a catback exhaust system hooks up to is not a real cat, rather just one there for looks I guess.  I've heard it was put in for visual emissions inspections, but that could just be rumor.  Either way, the fake cat has nothing much in it at all anyways.  You're real cat is right off the header, and has an O2 sensor.  So you either have to get a Random Tech cat (I don't know the part #), or just get a Hotshot header (full header, unlike Greddy SS short header) and replace the fake cat with a real universal RT, or Carsound cat or something.  That's if you're worried about emissions.  It'd probably sound better with a cat on there too.  But if you don't want to, just weld a pipe in where your fake cat is with the Hotshot header and that's the freeist flowing exhaust you can get.

11-27-2001, 09:05 AM	#12
Guest Posts: n/a	what kind of problems with the ECU w0uld you experience without the cat...isn't there a possibility it could make your car run worse/slower?

11-27-2001, 11:19 AM	#13
vancouvers14 Zilvia Addict Join Date: Jul 2001 Posts: 868 Trader Rating: (0) Feedback Score: 0 reviews	well, the other issue is legality.  running no cat is illegal in most places.  plus, if you have a catback, it will get obscenely loud.  i set off probably one car alarm a week, with my exhaust.  i couldn't imagine it getting louder

11-27-2001, 12:24 PM	#14
HippoSleek Nissanaholic! Join Date: Aug 2001 Location: elsewhere Posts: 2,081 Trader Rating: (0) Feedback Score: 0 reviews	I agree that removal of the cat will lead to a CEL/code.  Yes, this will cause you engine to go into a "safe mode" which will make it run like dookie.  I also 100% agree with yenpit's statement that the science of cats has improved so that you are not going to see huge gains by removing it or upgrading to a high-flow unit.  Some - but not huge.  If you are making huge power or using an engine/header that is not designed to have a cat that may be another story - but for basic bolt ons, I've not seen straight pipes give huge gains like people would like to believe. The cons are sound and pollution.  I'm no tree hugger, but having my car smell like a '71 Catalina is not high on my list of mods <img src="http://www.zilvia.net/f/iB_html/non-cgi/emoticons/wink.gif" border="0" valign="absmiddle" alt=';)'>  For the money, I think there are other mods that would give you more power with fewer drawbacks. BTW: after having this debate about 16 times, I believe that most '95s are OBD I with a single, pre-cat o2.