Trying to get Wiring diagram
 

I have two CEL codes. One for the EGR and the other for the o2. When I first started doing this swap I couldn't figure out where to get a diagram that showed the colors coming off the o2 sensor and the corresponding pins. I have a factory service manual on cd but it only has the wire colors for the harness side of the plug which isn't doing me any good as I have an HF to VX conversion. It seems as though many people use the factory service manual and helms interchangeably. Are they the same thing? Mine has the fuel and emissions section but it just looks different from the one I saw on here before. Does anyone remember where on the forum I can find the post with the diagram.

I'd worry about the EGR stuff before the O2 sensor. often in odbII cars you can get several codes because of one failure. EGR malfunction could possibly affect o2 sensor readings (sending an o2 sensor code) but the opposite is highly unlikely.

If I understand correctly, you have a harness whose plug doesn't match your ECU and your wiring diagram only matches the harness. Having the diagram for the other type of harness is the same as having the diagram for the ECU, right?

I don't remember a posted diagram, but someone posted a link to a site where you can download whole service manuals. I can't find it now. Here's some sites that aren't not as good but might have some:
https://hondatech.info/search/civic
https://www.hondahookup.com/manuals
https://www.manualnguide.com/guide/automobile/honda/

Hmm...I wonder if this one was it:
https://www.spoonhonda.com/SearchResults.asp?Cat=119

If you can read in Spanish, maybe one of these manuals will help:
https://www.gassavers.org/showpost.ph...&postcount=145

I found this thread which won't help with wiring but has all kinds of other info -- and you should post whatever wiring diagrams you find in it:
https://www.gassavers.org/showthread.php?t=7282

Oh, and don't forget that your local library may have what you need, or they may have access to online service manuals.

Yes. Helm, Inc. prints and sells copies of the Honda and Acura factory service manuals, among others. For some reason or other, the term "factory service manual" or FSM just never solidly caught on with the Honda enthusiast crowd... Everyone calls it a Helm's manual, in contrast to a Chilton's or Hayne's manual.

I got the code for the egr to go off. As it turns out the conversion harness I got didn't have pins or the wiring for that matter for the egr. I pinned the obd1 plug and spliced into the obd0 side of the harness. It still periodically throws the code 48 but now it is accompanied by code 41. I have also noticed that if I coast with the car in second the light always comes on when it gets down to about 1500 rpm. It still also hesitates a great deal while in lean burn. I have seen lots of people with this problem does anybody know whether or how they ever resolved the problem. Does anybody have any ideas. Does anybody know of a way to check to see if the timing belt is off a tooth or two.

Unbolt the valve cover and remove the upper timing belt cover. There should be three lines and an "up" indication stamped into the face of the cam gear. You'll be using the two lines that are directly across from eachother. Ignore the third line - it's for 1.6 liter motors.
Turn the crankshaft (turn the crank pulley by hand, or use a ratchet on the crank pulley bolt) counter-clockwise until "up" on the cam gear is close to being all the way up. Look at the back half of the upper timing belt cover... The part bolted to the cylinder head. There should be a pair of pointers molded into the plastic on opposite sides of the cam gear, near the valve cover mating surface. Continue turning the crankshaft until the two cam gear lines on the cam gear face align with the pointers on the back cover.
Now, look down towards the crank pulley. You should see a notch and pointer molded into the lower timing belt cover, forming a sight. Look down the sight at the crank pulley, and you should see a notch cut into the rim of the crank pulley. If you look at the pulley, you will find there are actually four notches: three in a group, and one on it's own. The group of three is used for setting the ignition timing, the remaining one is the top dead center indicator - what we're looking for.
If the TDC notch on the pulley isn't lined up with the sight, rotate the crank pulley until it is and then look at the cam gear to see how far off it is and in which direction.

For anyone else's info, non-vtec D15 motors use the valve cover mating surface as the pointers, rather than ones molded into the timing belt back cover. D16s use a pointer molded into the back cover, directly under the gear (it sticks out so it's plainly visible).

Do you think think that might cause this problem? I'll try that out tomorrow. It's supposed to get down to minus 30 tomorrow so I'll have my work cut out for me.

The cam timing being off a tooth generally causes a very lop-sided power band. Either you get very little low-end torque that picks up to normal levels at high RPM, or a fair amount of low end torque that chokes off at higher RPM.

In Baltimore? o_O

Here is another website for some Honda Factory Service Manuals including the 90-91 USDM Civic (opposed to the 1990 JDM Civic that's everybody else has).

spoonertuner.com <-- Hit the manuals tab

-30 in Baltimore?

I have the service manuals. I was asking about a wiring diagram that somebody posted that was not out of the service manuals.