1998 Civic LX to HX D16y5 conversion has begun!

[MPGomatic]

Great thread, Firehawk618!

We need to rescue all of the HX Manuals.

I searched for a clean HX for eons before finally landing one with 122K for $2700 last spring. My best tanks have been in the 45 MPG range so far, with Michelin Defenders, Valvoline Synpower, cheap-o eBay lowering springs, and shadetree aero (skirts & airdam).

I've been shooting the build all along for a wacky series pilot: https://www.youtube.com/playlist?lis...R754kIg_V8Aahm ...

Aero is the big nut to crack. I have crazy dreams about wind tunnel-tested true aero bumpers, skirts, and underbody cladding. Solving the rear bumper 'parachute' issue with functional aesthetics is a key issue.

If you haven't added a short-throw shifter and poly shifter bushings yet, I highly recommend it ... so much bang for the buck.

I have a new Magnaflow manifold/cat and a (third) AutoMeter 02 sensor/gauge ready to install (need to drill the manifold and weld on a bung), but I keep thinking that what we REALLY need is a simple Lean Burn Indicator APP to run on iOS/Android.

[Chrysler kid]

My 96 only engages lean burn at 55mph, no matter what gear I'm in.

With my commute being only city the lowest speed lean burn will stay active is 51mph

There are no long hills where I live so no engine off coasting

I have a small volt meter hooked to my secondary 02 sensor to verify lean burn that is discreetly mounted in the dash. Otherwise I use a vacuum gauge for most of my driving

[Chrysler kid]

Oh and hawk did you have to run an extra wire to the oxygen sensor to run the 5 wire oxygen sensor? Or was the 5 pin plug the same as the lx 4 pin?

Oh and the ideal car to swap to be an hx would be a 96-97 hatchback cx or dx with a manual trans. Automatic cars run different sensors on the intake manifold

Don't quote me on this one but I thought the change from obd2a -> b were only minor changes in a few sensors in the engine bay

[Baltothewolf]

HX for 1800
1999 Honda Civic HX For Sale !

Another one for cheap:
1998 Honda Civic HX 40mpg Clean Title***VTEC E

[Xist]

It kind of seems like a DX or LX with a VX transmission would actually work better than an HX, and then you can have four doors without worrying about the expensive oxygen sensor.

[Xist]

It kind of seems like a DX or LX with a VX transmission would actually work better than an HX, and then you can have four doors without worrying about the expensive oxygen sensor.

[firehawk618]

Originally Posted by Baltothewolf

HX for 1800
1999 Honda Civic HX For Sale !

Another one for cheap:
1998 Honda Civic HX 40mpg Clean Title***VTEC E

ROFL that 1st one, wow, that's pretty much scrap materiel there.

The 2nd one has already been deleted.

[firehawk618]

Originally Posted by Xist

It kind of seems like a DX or LX with a VX transmission would actually work better than an HX, and then you can have four doors without worrying about the expensive oxygen sensor.

Pretty much but the D16y7 seriously lacks low end torque where the D16y5 shines.

As far as that pesky expensive o2 sensor goes, I picked up a brand new one on Rock Auto right before my engine swap for $29.32 shipped.

YES you read that right. It was listed as distributor close out! They listed 4 in stock so I ordered all 4. The next day got notified they actually only had 1 so I did end up getting 1.

I thought for sure they'd send me the wrong one.

It's been working just perfectly.

[figit090]

Originally Posted by firehawk618

I have stopped trying to force leanburn to happen. I have found I'm much better off to just use 5th gear even though that may put me at too low of RPM's for LB to happen.

When I do get the VX gearing installed I will basically lose any chance of LB when in 5th gear unless I'm above 70mph. I will again experiment with a lower gear to get LB vs lower RPM.

One thing I have been doing now though is killing the engine at stops when possible and EOC everywhere possible.

My commute to work is mostly uphill travels therefore my commute home is a lot of down hill travel. I have been taking advantage of this. I can coast roughly 4 miles every day!


Here's the breakdown about the sensor I was talking about, bare with me as honda made this as confusing as possible.

Fuel tank pressure sensor:

1996 EX only has it
1997 Coupes all have it IF they are EX or HX
1997 All California emissions cars have it
1998 All cars have it

If you find a 1999 or 2000 don't bother unless it's already a HX. The reason is honda went from obdiia to obdiib in 1999 and the body side of the harness is completely different. It will NOT be plug and play HOWEVER the HX stayed obdiia it's entire span from 1996 to 2000.

One work around I can think of is get an ecu from a 96 HX as it will not expect this sensor therefore you won't have to mess with it.

Confused now? lol

Honestly I would say just get whatever chassis you can as long as it's 98 or older and whatever HX swap you can and make it happen. The worst case scenario you will have to swap fuel tanks and run 2-3 wires.

I just got REALLY lucky I started with a 98 LX and stumbled upon the swap out of a 97 HX. The stars and planets aligned for the easiest possible conversion. I had to run ZERO extra wires and had to re-pin ZERO connectors. Straight up plug in and go.

I do really like the D16Y5. It has SO much more bottom end torque than my D16Y7 or D16Y7 with the Y8 head EVER did. It's really easy to putt along at 1200 rpm's and even take slight inclines without down shifting.

It seems like this engine is impossible to lug.

Ironically, there's a car I want 44 minutes away from where you are...but 550 miles from where I am. WTF?

OMG.

can't wait until one comes up near me...

Thanks for the info on the swap...I will probably not get the chance to do that like you did but i'll keep my eye out for a blown-engine 'mechanics special' haha.

[Chrysler kid]

Originally Posted by figit090

Ironically, there's a car I want 44 minutes away from where you are...but 550 miles from where I am. WTF?

OMG.

can't wait until one comes up near me...

Thanks for the info on the swap...I will probably not get the chance to do that like you did but i'll keep my eye out for a blown-engine 'mechanics special' haha.

I would not turn down a clean 5 speed 92-00 civic coupe or hatch regardless if it is an hx or not. I really wanted red or white civic ex initially