Has anyone thought about or tried replacing the OEM exhaust system on a 92-95 CX/VX with an aftermarket or OEM stainless steel header-exhaust?
I have a seen a SS 4/2/1 header-exhaust that has an O2 bung on what is essentially the equivalent to the 2/1 exhaust pipe 'A' on the 92-95 DX hatchback. However, the DX HB O2 sensor is located in the side of the 4/2 header at its bottom end (and not in the 2/1 pipe).
It shouldn't hurt anything if the L1H1 sensor is a little further down the exhaust stream should it? Assuming there is enough clearance to put the L1H1 in underneath which I have my doubts about.
I would like a 4/2/1 header-exhaust to replace the OEM 4/1 header-exhaust. It would definitely be unique but would it work?
My VX's exhaust is on its last legs and part of it is not OEM anyway (exhaust pipe 'B' is a custom made pipe from a muffler shop probably). I am thinking it wouldn't cost too much to put a stainless steel header/exhaust with a new cat on the VX but the main complication will be to extend the wire length of the L1H1 from its new location under the engine. I think it could be several feet longer. I'm not sure if this relatively small increase in length would be enough to affect the voltage for the L1H1 or not.
Is it possible to use the 99 DX HB OEM exhaust with the 92-95 CX/VX? I don't see why this wouldn't work because it has a 4/1 header-exhaust that is pretty darn close to the 4/1 header of the CX/VX. Maybe the 99 exhaust is stainless?????? Would it fit? The 99 DX is a 1.6L so the header could be a different size at the block, I don't know. I'm pretty sure that the 92-95 1.6L D16Z6 block was the same as the 92-95 1.5L D15Z1 block with the main difference being the cylinder heads were different. Yeah, I know the 99 DX has two O2 sensors but I could plug the lower O2 bung.
A new, complete OEM CX/VX exhaust system (without header) including the cat is about $400 and I'm pretty sure Honda has not made these replacement parts stainless for the 92-95. I have not searched honda-tech yet but I'm fairly certain those who have replaced their headers don't have the same issues with the 5-wire sensor that those of us with the D15Z1 engines have.
Even if you have not tried doing this, I would appreciate feedback from the gassavers regulars (TomO, Matt T and SVO Boy in particular) to see if anyone thinks that I might be able to find a stainless steel exhaust for the VX. I want this to be the last exhaust system on this car. Michigan winters really put a strain on them believe me.
It won't help your FE, but it will dramatically increase your performance which might make you want to lead foot it more...
I installed a 4-2-1 hedmen tork-step header and the performance has been great but it had no affect on my gas mileage when I drove normally.
If I could do it all again I would have installed a cheaper 4-2-1 stock manifold that has the O2 sensor in the cast iron manifold exhaust manifold and the stock tubular steel down pipe to go along with it. I believe this came on Civic EXs from 96-98. There is also a fully tubular steel stock one from the 99-00 EX, but the cast iron will hold in the heat better and keep the O2 sensor temperatures better. I have seen them sell for $20-$40 and I would wait until you found one for that price.
If you take the wiring out of the loom you do not have to cut any wires. It reaches.
Any d-series exhaust will work as long as it has provisions for an O2 sensor.
Let me know if you need help finding one. I'd check honda-tech and clubcivic.com. I have seen them on Craigslist and houston-imports too.
The 99-00 EX header is better if you want a 4-2-1 style tubular header for your car. The O2 bung is situated the same as the VX (it reads all four pistons, but lower down in the system) and the sizing of the primaries is better to keep exhaust flow up.
I wasn't able to get an OEM header like that so I went with the $40 shipped Ebay special Stainless steel 4-2-1 header with two O2 bungs in it. One in the #4 runner and one located just before the collector to read all four runners. Unfortunately, the lower O2 bung is positioned such that the L1H1 can not be installed there due to its taller than most O2 lengths. It would contact the inner CV boot and shred it. I'm handy enough with a welder that I'm installing a new O2 bung just in front of the CAT so I can place the L1H1 where it theoretically should be (reading all four runners).
I collected all the parts I needed for my VX custom exhaust for $115.
A breakdown of part:
Ebay SS header = $40
New CAT = $30 (deep discount from a parts store)
Two U bends 2" mild steel = $20
4' length of straight 2" + Cherry Bomb Turbo Muffler = $20 (new but bought from private party online)
3/8" non threaded rod 4' length = $5
Two 2" Cherry Bomb resonators each 29" length = Free (friend had them laying around)
My friend and I did all the cutting, assembling, and welding, so that was basically free.
Ideally, all the formulas I used stated that I should have went with 3/4" primaries on the header that stepped down to 1/2" but the cost to make a header like that from scratch out weighed $40 Ebay header. The headers' dimensions weren't all that bad anyways. The rest of the system should have been 1 3/4" exhaust tube, but that was also cost prohibitive considering that particular size exhaust tube was twice as much as 2"
The system I put together is at most only one decibel louder than stock under WOT only. Otherwise the whole system is just as quiet as stock.
The one drawback that I've noticed now in the 2000+ miles I've put on this system is, I believe, due to the O2 currently being located on the #4 runner. I experience a very slight hesitation after coasting down from highway speeds and putting the car in third or second gear to continue on without stopping. I believe it is due to the sensor reading only the #4 runner. That runner is the one associated with running slightly lean due to the placement near the plenum of the intake manifold.
So once I get the new O2 bung in there I'll post my results. But I am extremely happy on how this system turned out for me. I would like to mention that after I finished welding the system, I painted the entire thing with High temp Aluminum paint, effectively Aluminizing the mild steel for longer life. So far, after 2000+ miles, there is no sign of surface rust or the like. I've used this paint on other exhaust systems I've done before, on cars that see MN salt with winter and the paint holds strong and protects the steel perfectly.
I hope this gives some insight on what can be done with the exhaust system.
I have a 1993 accord, which I did install a stainless header on. I just bought an el-cheapo header off eBay for 80 bucks. There were some fitting issues, but nothing I couldn't resolve. The original pipes had a leak and were looking pretty sad, so It was time.
I did have to extend the wire to my oxygen sensor by about 3ft. The oxygen sensor is placed just where the 2 pipes join to form 1, which is underneath the car. Past that, it works quite well. It has had an effect on the sound, but I am not sure about fuel economy yet.
My first observation is that headers get very hot! Hot enough that the stainless turns yellow, and then purple, after about a week of having it installed.
There's a link in my sig about exhaust upgrades. Basically, if you're driving with any concern at all for MPG you're only flowing a fraction of what your exhaust can handle freely. Therefore, I wouldn't worry too much about buying an expensive muffler and I definitely wouldn't invest in dual exhaust for fuel economy (or for a car with only four cylinders!).