daluv

I recently bought a 1999 4-door automatic Civic EX with a knocking motor. The only motor I could find to replace it locally and for a good price was a D16y7 (non-vtec motor from a 1999 LX.)

I swapped the EX motor and transmission with the non-vtec motor with its matching transmission, as well as the non-vtec engine harness and non-vtec computer.

I did not get any exhaust pieces with the non-vtec motor, so I reused the EX setup, knowing I would face a problem with the O2 sensor locations.

I was able to strip the wire loom enough to get the O2 plugs on the engine harness to reach the EX sensor locations. I am now throwing a code for the 2nd (downstream) O2 sensor (of which both sensors are brand new,) and also after the engine runs for about 2 minutes, it starts bouncing (revving up and down) and does not go away.

All of my engine harness plugs are where they are supposed to be, as well as all vacuum hoses.

Any ideas as to what I missed? Why my brand new O2 sensor is throwing a code?

Former User

Did you solder and heat shrink wrap the spliced O2 sensor wire?

What specific code is thrown?

The idle issue is likely separate from the O2 sensor code. Check for a disconnected vacuum hose.

daluv

Ill double check the code when I get out of work and post the specific one.

There wasn't any soldering/cutting or splicing done. I removed enough portions of the factory wire loom on the harness to the point where I was able to get everything to plug in without extending any wires.

daluv

P0141

Heater circuit Bank 1 Sensor 2

Bad wire connection? Don't understand why since I haven't spliced anything. Going to run a volt test now.

Former User

Check whether 7.5A dash fuse 15 is blown.

daluv

Fuse 15 is good. Volt test says I'm not getting any power to my white/red stripe wire on my harness plug. Any idea how to get power to it? Or why that would not have power?

Former User

Voltage test fuse 15 while it is installed in the fuse box and the key is in ON(II). Click the Test Fuses link in my signature.

The power wire for the secondary O2 sensor heater is Blk/Yel, not Wht/Red.

daluv

I did some bouncing around between the upstream plug (working fine) and the downstream plug. Every pin has the same voltage except the white/red.

I'll check the fuse now. Was also going to see what the wire reads at the ecu.

Former User

With the O2 sensor unplugged and the key in ON(II), the Wht/Red wire terminal in the harness connector should basically have no voltage. In contrast, the Blk/Yel wire terminal should read battery voltage.

Regarding code P0141, there are only 2 wires to concern yourself with -- Blk/Yel and Blk/Wht.

Voltage test the Blk/Yel wire and test the Blk/Wht wire for an open.

If both wires are fine, then resistance test the heater element of the sensor - it should read 10-40 Ohms.

daluv

The red/white on my upstream (with key on II) reads .5, the red/white on the downstream reads .0001. My black/yellow wires on both read the same as my battery. And the green wire reads .5 on both.

Former User

Test the Blk/Wht wire for continuity between the sensor plug and ECU A8.

http://www.phearable.net/tech/wiring...schematics.gif

Ohm test the heater element.

daluv

No continuity on blk/wht at A8

daluv

*between plug and A8

boostedej1

egr valve? different ecu?

daluv

Ecu and harness match the motor, as stated above. O2 code 0141, not egr.

Former User

The wire is broken. This is the problem. Find the break and fix it or run a new wire.

daluv

Yep, I ran a new wire and that took care of it. Still idling weird though, bouncing from 1,000 to 2,000 rpms.

Former User

Also bleed the cooling system.

daluv

Cooling system is bled. Going to take the throttle body off and clean up all the components, I think the Idle Air Control Motor might be dirty. Also going to re-check my vacuum lines.

When I put my hand over the first portion of the intake piping (the box on top of the throttle body,) which would normally stop a motor from running, in my experience, it will idle fine at about 800ish rpms after warmed up. As I start taking my hand off, the idle starts climbing, and as soon as my hand is off, or the rpms reach 2,000, it starts surging.

daluv

Also, thanks a bunch Ron! You've been super helpful man, and it's very appreciated!!!

daluv

Cleaned the idle air control motor, no more surging!!! Thanks for the help!!!