just thinking in my head if you buy a cheap 2 to 1 header and cut the single collector off to make 2 collectors and run the pipes out to the rear wheels.... thus having cyl 1 and 3 on there own collector and cyl 4 and 2 on the other now im stumped on the o2 sensor will i have to run 2 pig tailed together or just keep the single o2 sensor?

 

I would just keep the single 02 sensor just or simplicity. But don't the '96 Accord have two 02s? One upstream and one downstream?

 

ok my question is do you understand what im saying? kinda making a header for both firing cycles to give the choppy sound like a v-twin i have seen it done many times in the family but with old school carb'd engines and the rear o2 sensor before the cat is what has me at a stop....should i buy 2 of them and wire them together on one plug to make it easy to take it all out and go back to a single pipe

 

what you're describing is not the common understanding of "true-dual." you would need two banks of cylinders for that. that may be causing some confusion.

so basically you want to run your secondaries all the way to the rear of the car... for the sound. fair warning, it will be heavier, more complicated and not likely to perform as well as more traditional systems. anyway, pairing 1-2 and 3-4 would give a more noticable, choppy sound. (so would a big cam...) for the O2 sensor, you could probably get away with running the O2 in one side or the other. the ECU wouldn't know the difference, however if one of the two cylinders not feeding the O2 were running poorly you could cause damage (lean) or waste fuel (rich).

my suggestion is that you run a big, lopey cam (with a good tune of course) with a traditional exhaust.

 

i was thinking use a bisi level 2.5 or 3 for a cam im wanting to keep the exhaust short as possable with near no bends and dump out inbetween the 2 doors (96 accord) with turndowns and maybe a 12inch glasspack if its too loud on the top end and for you saying 2 cyl's wont be read thats why i was asking if i need 2 O2 sensors to pull this old school trick off

 

Please don't. I know there's the whole 'It's your car and do what you want' mentality, but I can tell you there are certain cars that style works for and a 4 door 16 year old car is not one of them. Spend your money on a nice exhaust system and keep a single outlet. You will be glad you did when you're done.

*edit* Added to this, you really can't do a straight back exhaust system without bends. The Accord's tunnel has two near 90 degree bends in it right around the back seat area to get it off to the side. You would be sacrificing ground clearance to have straight exhaust.

 

yes im asking about the one down stream...would i have to run one in each pipe?

 

just make an unequal lenght headers,it will sound like a turbo subaru

 

OK IC what you were asking. True dual...... Thought about it for a minute......... And that's about as far as it went!

You only need to stick it in one pipe. You should probably instal it using a spark plug defouler over it. That is the only option that I have seen to trick the down stream O2 into thinking it is still behind a cat.

Other way would be to loose the second O2 all together by running a conversion harness and a chipped OBD1 ECU. or you could run a conv. harness and a stock 94-95 OBD1 Accord ECU.

 

Are you doing it for the sound or the performance? Either way I don't see a point.

 

What you are planning on doing is not going to work.

If you want the 'dual exhaust' look, like found on later V6 Accords, I suggest you find a complete cat back system for a V6 car and modify it, and your car, accordingly.

 

is what im wanting to do can be done my family has done it many of times but on carbd engines now with this newschool "efi" you have O2 sensors and im stumped how about this if i get 2 O2 sensors and wire them together on one plug will the ecu still get a reading from all 4 cylinders? now mind you one will be in one pipe and the other

 

the subaru motor and the honda motor are different so it would not sound like a turbo subaru

everyone already said it would be the best idea to go along with you plan...you would be seriously lacking backpressure taking away bottom end power, risking messing up your exhaust valves, and messing up the computer and cat's since it would take longer for your 02 and cat to warm up....also in most state you will most defiantly fail smog since you wont have the backpressure needed for the EGR and the idea of you moving the cat would also be illegal

like others said if your dead set on making your car dual exhaust mod the axle back from a V-6 accord

 

Since when does the EGR need back pressure and what about back pressure is required to give the engine low tq?

You do not need back pressure for low end tq or for the EGR system to work or to pass emissions. I wish the inaccurate descriptions of "back pressure" would just go away for a while.

 

i doubt anyone has ever even tried this since it is pointless other then to make the exhaust loud. i dont think wiring two o2s together would create the right signal to send to the ecu leaving you in limp mode. yes it will work on the old carb'd vehicles but these honda have the air/fuel ratio controlled by sensors and the ecu

like stated above if you put it in just one pipe the ecu will not know if the other two cylinders are not operating properly. if you want a loud exhaust just go 3" all the way back...again pointless

 

The rear O2 does not control fuel ratios. It is there to check the level of exhaust gas emissions after the catalyst.

Running a dual exhaust could potentially rob you of some exhaust scavenging. However, I'm not convinced that it will hinder a stock engine all that much, be it performance or emissions. To be honest, there really isn't much room down the exhaust tunnel as previously mentioned.

 

so i guess the class that i took and learned alot about this type of stuff that was not only taught by one of the head guys at toyota but he also helped create OBD2 was all a bunch a bs right and that guy had no idea what he was talking about??

backpressure is real whether you want it to be or not

the rear O2 DOES control long term fuel ratios in the OBD2 cars

 

you learned a lot of outdated information. Maybe we'll be half impressed if you can remember the name of "one of the head guys at toyota."

no one said back pressure was a myth. the need for "back pressure" in order to make low end torque or spare the exhaust valves is a long perpetuated misconception. exhaust flow velocity and scavenging are what you're aiming at - bigger is better doesn't hold true in fluid dynamics.

long term fuel trim is computed from short term fuel trim... which gathers data from the primary O2 only.

 

Not hard to remember when i have my Bureau of Automtive Repair certification right in front of me...Tom Brenneman was his name

class was for CURRENT California "Advanced Clean Air Car Course"

the reason why i said its bad for the exhaust valves is due to the fact how the exhaust valves will basically get warped once the coldish air hits the hot exhaust valves causing them not to seat right



edit: just to show that that the "outdated information" that i learned in my class isnt so outdated
http://smogcheck.ca.gov/80_BARResour...criptions.html

so yea i would think that what i learned wasnt so outdated

 

well i guess bye bye old school tricks....what is this yall are talking about the rear section from under the v6 accord? could someone inform me on this or is it like the 90s caddys with the "y" to two mufflers and if thats the case then im goin to stick with the original single out

 

I'm not sure what you thought you may gain from not merging the primaries together into a single exhaust. On flat crank engines there is no need to do what you suggest. A 4-2-1 header will do a better job of scavenging the exhaust gasses than what you propose.
Yes its similar to the FWD Caddy dual outlet exhaust system.

 

its a little family trick that i love the tone of and was wandering if could be done on modern vehicles...and with the rear section could i go and cut one from a junkyard accord to make my own muffler/tip setup? is what the family did was chop the header put a 12 inch glasspack and a ansa single resonated tip....produced a tone of its own! i would love to bring the tone back but i guess im goin to have to use a " Y " off of a junkyard car if possable

 

What coldish air? were not talking about running open headers. This sounds like information used when talking about old cast iron head V8s. In the ops setup the exhaust will still maintain it's original heat. The OP isn't taking about putting a 5" exhaust on his car. He didn't even mention anything about making it any larger than stock.

 

You car isn't going to sound like a V-twin with a dual exhaust. It will sound like a four cylinder engine with two exhausts. The reason this trick works on older carbed engines (I'm assuming you are talking about GM V8 engines or a 90* V6) Is because crossplane crank V8 engines have an uneven firing order within each cylinder bank. 90* V6 engines have a gap in the firing order.

V-twins get their sound from the odd angle between cylinders and the resulting 270-ish degree gap in cylinder firing. Honda motors fire every 180 evenly. You will not get the sound you are looking for.

The V-twin is a shitty engine design from the early 1900's, it has poor mechanical balance and is a design that is outdated by 50+ years. Why would you want your car to sound like that?

Secondly, your primary O2 must be in the exhaust stream of all 4 cylinders. Splitting your exhaust before the collector would stop you from doing this.

I ran my O2 on the #3 pipe on my header when I first got it. Failed emissions miserably. What I found after checking the plugs is that while the #3 cylinder ran at proper a/f mixture, but the #4 ran lean, and #1 and #2 both ran rich.

If you pigtail the oxygen sensors it will not work. They are two voltage sources which read different voltages wired in parallel. You won't get a useful signal with that type of configuration. Voltage sources can only be wired in series.

If you want to do it I can't stop you, but it will cause lots of problems with your car and won't do what you are attempting to accomplish. No matter what you do it, the car is still going to sound like a honda.

 

doesnt have to be larger than stock....if he is running the same size as oem pipping on both exhausts than it would be the equivalent to one bigger pipe