ehudson

I got a P1166 and P1167 code on my 99 Accord. I have replaced the Primary O2 sensor and tested the secondary O2 sensor. The orignal primary sensor had an "open" circuit on the heater leads (no resistance=heater circuit blown). I intalled a new sensor and re-set the computer. After starting the car, got a P1167 (primary O2 sensor heater malfunction) again. The O2 sensor tests good using a "out of car" propane torch test, and the heater circuit leads have ~9 ohms so the heater looks good. With the sensor installed, when I first start the car, I have approx. 0.3 volts on the signal leads, then it drops to 0 volts at the same time the check engine light comes on. I can unplug the sensor from the harness, and it shows 0.9 volts with the car running, but goes instantly to 0 when I plug the sensor back in. The heater circuit has approx 12 volts on it, so the heater circuit fuse is not blown. Has anyone seen this? The sensor I bought looks just like the factory one, but is a "universal" type from Bosh.

ehudson

I solved the problem. P1167 and P1166 codes relate to the primary O2 sensor heater malfunction.
I tried two different O2 sensors, a "universal" sensor from Autozone and a supposedly OEM sensor from O'Reilly's. Both of them caused the car to throw a P1167 code and run rough. I finally purchased a O2 sensor from Honda, and it fixed the problem. It turns out that none of the aftermarket probes from Bosch or Denso will work on a ULEV (F23A4) 4 cyl. engine. Honda had different part number probes for the normal VTEC 4 cyl. and the ULEV Vtec engine and the probes look different and have different length cables. The computers at O'Reilly's, Autozone, or NAPA made no distinction between these two engine types.

RKV

is that the same thing as code 67(catalytic converter inefficiency)? i notice the P1167, the last 2 digits are 67, wasnt sure, cuz i have that code

ehudson

2 digit codes are usually from checking light flashes. Your code 67 is the same as a P0420 read with a scanner. It means "Catalyst system efficiency below threshold" This can sometimes be caused by a bad Catalytic converter or a problem with the O2 sensor located after the catalyst.

I found this list of codes elsewhere on the web. Maybe it will help...

__________________________________________________ ______________
For those of us who won't(can't) spend $$$ in OBD-ii scanners; there is an alternative to find out
about codes and that CHECK ENGINE light that is driving us crazy:
1) Go to Autozone and have them read your codes (it's free)
or
2) See the instructions below

WARNING!!!: USE AT YOUR OWN RISK.

HOW TO OBTAIN TROUBLE CODES MANUALLY (6Th Gen Accord - V6 & I4)
1) Find the Data Link Connector (DLC) located under the instrument panel in the driver's side.
2) Jump terminals 8 and 13 by connecting them with a wire/cable.

...............________
...._____|________|_____
.../|1...2...3...4...5...6...7...8|\
../.|================ |.\
./..|9.10.11.12.13.14.15.16|..\
/------------------------------------ \
DATA LINK CONNECTOR (DLC)

3) Turn the ignition key to ON and observe the "CHECK ENGINE" light. It will flash the trouble codes. For example: 2
long flashes, pause and then 3 short flashes = 23 = P0325 = Knock sensor circuit fault.
One short flash = 1. One long flash = 10. If there is no trouble codes, the light will not flash.

Flashes.....Code(s)............................... ..........Description
1...............P0131,P0132....................... .........Primary heated O2 sensor circuit low/high voltage
3...............P0107,P0108....................... .........Manifold Absolute Pressure (MAP) sensor circuit low/high voltage
4.............. P0335,P0336.................................Cranks haft position sensor
5.............. P1128,P1129.................................Map sensor circuit low/high voltage
6...............P0117,P0118....................... .........Electronic Coolant Temperature (ECT) sensor circuit low/high input
7...............P0122,P0123,P1121,P1122........... Throttle position sensor (TPS) circuit low/high input
8...............P1359,P1361,P1362................. ....CKP/TDC sensor 1
9...............P1381,P1382....................... .........CYP Sensor
10.............P0112,P0113........................ ........Intake Air Temperature (IAT) sensor circuit low/high input
12.............P1491,P1498........................ ........EGR valve
13.............P1106,P1107,P1108.................. ...Barometric pressure sensor
14.............P0505,P1519........................ .........IAC valve
17.............P0500.............................. ..............VSS fault
20.............P1297,P1298........................ .........Electric Load Detector (ELD)
21.............P1253.............................. ..............VTEC
22.............P1257,P1258,P1259.................. ....VTEC
23.............P0325.............................. ..............Knock sensor
41.............P0135,P1166,P1167.................. ....Primary heated O2 sensor
45.............P0171,P0172........................ .........System adaptive fuel too lean/rich
48.............P1162.............................. ..............Primary heated O2 sensor
58.............P1366,P1367........................ .........TDC sensor 2
61.............P0133,P1149,P1163,64,65............ Primary heated O2 sensor
63.............P0137,38,39........................ ...........Secondary heated O2 sensor
65.............P0141.............................. ...............Secondary heated O2 sensor
67.............P0420.............................. ...............Catalyst system efficiency below threshold
70.............P0715,20,25,30,40,53,58,63......... .Automatic transaxle malfunction
71.............P0300,P0301........................ ..........Random/Cylinder 1 misfire
72.............P0302.............................. ...............Cylinder 2 misfire
73.............P0303.............................. ...............Cylinder 3 misfire
74.............P0304.............................. ...............Cylinder 4 misfire
75.............P0305.............................. ...............Cylinder 5 misfire
76.............P0306.............................. ...............Cylinder 6 misfire
80.............P0401.............................. ...............EGR insufficient flow
86.............P0116.............................. ...............Electronic Coolant Temperature (ECT) sensor range/performance
90.............P1453,P1457........................ ..........EVAP control system leak
91.............P0452,P0453........................ ..........EVAP fuel tank pressure sensor low/high input

The codes that will not flash are as follows (will need code scanner):
P1607-PCM internal circuit failure and
P1705,06,38,39,53,68,73,91-Automatic transaxle failure

HOW TO CLEAR TROUBLE CODES (after fixing problem)
1) Remove ignition key (OFF)
2) Locate fuse panel on passenger's side (open door)
2) Remove fuse no. 13 (7.5 amp) for 10 seconds, and then place it back in.

I hope this info helps you, as much as it helped me.
Enjoy!

RKV

so if i changed the o2 sensor on my header(is that after the catalyst), does that mean it is a bad cat for sure? could my o2 on the catalytic converter be bad(primary o2)?

ehudson

The O2 sensor on the Catalytic converter is the secondary O2 sensor. The one on the header (nearer the engine) is the primary. The secondary O2 sensor is used to check that the catalyst is working properly. The secondary sensors reading is compared to the primary sensors reading by the computer to determine if the catalyst is converting the residual oxides in the exhaust. So a code indicating catalyst problems can be caused by the catalyst, or a faulty secondary O2 sensor.

RKV

thank u very much, now im back to square one, not sure if i should drop the $100 on an aftermarket OEM spec catalytic converter, or a genuine honda o2 sensor(have a friend that works at honda that gets employee discount)... sucks, cuz if i dont guess right, got to drop another $100 had a friend who is knowledgable and does engine swaps took out my cat, he said it looked fine, looked better than the used OEM cat i bought, he said it was white and clear inside, he could see through the other side(light passing), but he said there is like a 1% chance something inside could be bad, he gently shook the cat, nothing inside broken. thing is i used to be slammed 4 inches on the ground, and my header had a crack in it, so i thought maybe the cat got hit around also, initially he thought maybe that caused my code 67(the crack in my downpipe), any extra air would mess up my air fuel mixture, o2 would be reading wrong. changed my downpipe(header), still have the CEL. now i got to guess, my car bogs down at high speeds, around 80 mph, doesnt accelerate well, so i thought maybe its my o2, cuz i heard if the cat o2 is bad, car runs like shi*, so now im confused

ehudson

There is a test you can do on the secondary O2 sensor (the one on the Cat) It requires removing the sensor. You can mount the sensor in a vise, and hook up the wires to a digital multimeter. Put the meter on DC volts 20V scale and hook the green wire on the sensor to the black wire on the meter. Hook the white wire on the sensor to the red wire on the meter. Use a propane bottle torch to heat the end of the sensor until it glows red, the meter should indicate between 0.4 and 1 volt. The voltage should drop to 0.1 volt or less in less than 4 seconds when you remove the torch. You can also test the sensor heater element with the meter by hooking the meter wires up to the two black wires on the sensor. It doesn't matter what order. Set up the meter to read resistance (ohms) on the 200 ohm scale. The sensor should read between 5 and 10 ohms when cold. Resistance goes up when the sensor is hot. If you don't get any reading, the heater circuit is blown, if you get 1 ohm or less, the heater is shorted. Don't touch the green or white wires with the meter leads when the meter is set up for resistance, the meter induces a small current in resistance mode and could damage the O2 sensor.

RKV

thank you very much

200k

Just wanted to give props to ehudson for the plethora of good info, thx for the quality posts!