94 Accord ex stumbles and bogs down help.....
 

o.k. so.... from the top my sister in laws 1994 honda accord ex spun a rod bearing a month ago... i replaced the original block ( f22b1 ) with one from a junk yard ( f22a1 95,xxx on the clock only 80 bucks) changed the front and rear main seals , new head gasket and then put the head on....put the timing and balance shaft belts on and set the timing. hooked up all hoses , connectors , fuel etc. double checked the timing and on the first try started right up, and idled smooth. only code it thru was a code 6 (ECT) and a code 17 (VSS) shut it off and checked the wires and somebody had taken the plastic case of the harness and the ECT and the condenser fan switch were backwards fixed that and then no more cels. took it for a spin and it bogged or stumbled if i gave it to much gas but if i eased into it, it would pull fine to 5k rpms and then hit the rev limiter at first it would only do it from idle to about 2200-2600 :confused::confused::confused:. when i got back check engine light code 41 ( o2 sensor heater.... would the o2 put it in limp more???) tested the o2 and it seems to be fine, did a compression test all 151-155 with a leaky gauge, cleaned the EGR ports in the intake manifold (all but one were cloged). checked the TPS and the MAP both fine, got new plugs, checked the cap rotor and they look fine, took a known good set of wires and tried that. checked the coil and it checked out. basicly anything i could think of to check with a multi meter i did. cat is good took it off just incase...nothin. no air leakes at the throttle body or intake mani. IAC valve is good. ummm...the head feels like its getting hot but the temp. gauge is were its to be. could it be the grounds??? the car did not do this before. its like its not getting either enough fuel or enough spark. vtec pops fine it i feather it. its been like this for two weeks and i've searched and searched and fixed other problems (like the EGR ports) PLEASE any help or thoughts would be greatly apprecaited. thank you in advance PLEASE any help:confused:....

I thought that a bad O2 sensor would just set the fuel maps to some default level. I would check and clean the O2 sensor wire harness. Also measure the resistance in the heater circuit.

I would check that all of the vacuum lines are routed and connected properly.

All this information is available from a 94 shop manual that you can download from links in the Online Manuals thread in the DIY section.

Code 41 but how did you test the sensor? I think 1994 should have 10 to 40 ohms resistance between the 2 heater leads.

If the sensor is OK but you still throw code 41, the problem is in the sensor circuitry. That makes me suspicious of other problems in your wiring harness...

well last night i broke down and bought a set of wires and it fixed most of the issues. but it still hits the rev limiter or fuel cut or something at 5000 rpms and the only code its trowing is code 41 (o2 heater). i double checked all the vacuum lines....they are all good. i know the o2 is bad but would that explain why its hittin the rev limiter so early??? i know its runing in limp mode but my brother had a b18c crx that he ran without a o2 for like 6 months and it would pull to the red line everytime. i checked the ohms on the o2 and its just got coninuity between them... does that mean its grounded somewere??? would cleaning the clip for the o2 help??? and the clip is broken off on the corner if that matters.?. i just dont have money now to fix the o2 cause from what i hear only a oem one will do. but now i just wanna find out first if the code 41 will put the ecm in limp mode...and if not why would it be in limp mode if they are no other cels???? and by sensor circuitry you mean the harness or the ecm????

oh yea .....you can def. tell that someones hacked at this harness.... the TPS has been cut and spliced (well more like twisted and taped). could the grounds be why its going into limp mode???? thanks

I have ben told on multiple occasions that a bad o2 sensor could throw the car into limp mode but never experienced it first hand. Just my $0.02

thanks, anyone else running a 94-95 f22b1-2 accord obd1 with no o2 sensor? if so does it pull all the way to redline? ( 6500 ish rpms )...or like 4500-5000 rpms? and also does anyone know of a cheap place to get an oem o2 sensor??? i just cant imagine the o2 putting the ecu in limp mode, i get that it would dump more fuel but why would it hit rev or fuel limiter at 5k ??

..... just a thought when i reset the ecu and put the jumper wire back in it and turn the key into the on position..... my code 41 (o2 heater) shouldn't come until i start the car right????

I checked the 94 book for the o2 heater circuit, could not find it for the life of me... looked in my 99 book and the heater is driven by a transistor in the ECM. So you're saying you checked the heater and only shows continuity... well, that's not good. You may want to double check this, make sure you id the correct heater wires of the o2 sensor. Because if you only show continuity that means the heater is shorted out - I've never seen this before personally.
If you're correct that means the o2 sensor shorted out the driver in the ECM... not sure that's protected in some way not having the schematics of the ECM.
Let us know. You're correct on your last question, however if the cause is still present you'll get the same result.

If no O2 sensor, car would have to be in open loop mode. This may limit rpm, but I don't think this is same as "limp-home" mode. Manual doesn't provide any guidance on this issue.

Code 41 says to check O2 sensor heater resistance is in range of 10-40 ohms. If outside that range replace the sensor. You can get a universal for <$40 on ebay including shipping. I've used a couople and they worked fine.

good luck

thanks for the info. i'm gonna go to the junkyard tomorrow and pull a couple o2 sensors and see what i come up with...does anybody know if there are any other 4 wire o2 sensors that will bolt to the accord down pipe i guess????....like from a civic, integra, or any other makes and models like a 240 , eclipse or something like that???? i just wanna make sure thats it.

another question.... has anybody heard any horror story's about putting the head from a "f22b1" and putting it on a "f22a1" block ???? , and is 151-155ish across all 4 cyl. good for the compression ???

anyone know about the o2 sensors from different cars that would work with accord going to the junkyard first thing in the morning....thanks again

Looked up Denso part number on their site and cross-referenced it. Here are the cars it pulled up that use the same part number.

ACURA CL (1999) 2.3L L4 F23A1
ACURA CL (1998) 2.3L L4 F23A1
ACURA CL (1997) 2.2L L4 F22B1
HONDA ACCORD EX (1997) 2.2L L4 F22B1
HONDA ACCORD EX (1996) 2.2L L4 F22B1
HONDA ACCORD EX (1995) 2.2L L4 F22B1
HONDA ACCORD EX (1994) 2.2L L4 F22B1
HONDA ODYSSEY EX (1998) 2.3L L4 F23A7
HONDA ODYSSEY EX (1997) 2.2L L4 F22B6
HONDA ODYSSEY EX (1996) 2.2L L4 F22B6
HONDA ODYSSEY EX (1995) 2.2L L4 F22B6
HONDA ODYSSEY LX (1998) 2.3L L4 F23A7
HONDA ODYSSEY LX (1997) 2.2L L4 F22B6
HONDA ODYSSEY LX (1996) 2.2L L4 F22B6
HONDA ODYSSEY LX (1995) 2.2L L4 F22B6
HONDA PRELUDE SI (1996) 2.3L L4 H23A1
HONDA PRELUDE SI 4WS (1991) 2.1L L4 B21A1
HONDA PRELUDE SI 4WS (1990) 2.1L L4 B21A1
HONDA PRELUDE SI ALB (1991) 2.1L L4 B21A1
HONDA PRELUDE SI ALB (1990) 2.1L L4 B21A1
HONDA PRELUDE VTEC (1996) 2.2L L4 H22A1
ISUZU OASIS (1999) 2.3L L4 F23A7
ISUZU OASIS (1998) 2.3L L4
ISUZU OASIS LS (1997) 2.2L L4
ISUZU OASIS LS (1996) 2.2L L4
ISUZU OASIS S (1997) 2.2L L4
ISUZU OASIS S (1996) 2.2L L4

If you set your multi=meter on "CONTINUITY" then a good sensor will show that there IS continuity. Set the meter to measure "RESISTANCE" & measure it again in ohms. Your meter may read in kilo-ohms, so that would be 0.010 to 0.040 k-ohm.

Resistance measurements only work for the heater circuit (two same-color wires).

The sensor circuit is a very high, indeterminate resistance as I remember and does not provide any diagnostic value. The o2 sensor can be tested outside of car w/ a propane torch to heat the sensor and check output voltage to sensor leads. Many sources for details of this sensor test on www.

good luck

Early on it was code 41 for the sensor heater. So that's why I was just talking about the heater resistance.

The sensor itself will measure open-circuit when it's cold. At operating temperature it generates a small voltage (around 1 volt) but that type of problem would throw code 1 rather than code 41.

I'd just test the o2s heater, that's the initial issue. Meter selector set on ohms - omega symbol - low scale (X10, X100) or auto range if digital. Do not use the diode/continuity - see Jim's comment. Unplug the o2 connector, test resistance between same color wires (see Texas).
You can get one from the junkyard, and have the same results - need to troubleshoot first.
If you measure 40 ohms or so the sensor's heater is good, then go ahead and test the wiring - see Jim's comment - from the o2s back all the way to the ecm. We can help with the harness troubleshooting if we go past the sensor testing.
Let us know.

well went to the junkyard today found one obd-2 accord o2 and two 4 wire o2 sensors from a 92-93 accord and a 626 that fit and a hyundai dohc that looks identicalto the 94-97 accord ones put in the first,second,third...(cause three pluged right in) and .........good old code 41 :mad:! so clearly its in the wiring or the ecu......so can i run my own wires strait to the ecu to see if thats the problem???? i think i'm def. gonna need some help on the wiring its not my strong suit.... and the guy/girl that had the car before cut the wires coming from the ecu side of the harness going to the o2 sensor plug would that cause this????........ hmmmm maybe for a wideband o2.....and the map sensor wires cut for hmmmm?????..... would that explane why it was knockin ever so gently when she bought it and 2 months later spun a rod bearing...................turbo??? cause it has a empty gauge thing on the trim panel. but anyways what ever help , or maybe something simple like a fuse cause this???? car doesnt have either fuse cover so i woudnt know which one to check anyway i pulled like 8-9 of them and then gave up although i did find out why the radio didnt work....blown fuse....i'll test the wires coming from the ecu side of the clip......do they change colors before they get back to the ecu from the o2???? like i said wiring is not my thing so....... thanks in advance.

ok tested the o2 heater in the original and got 13.9-14.0 ohms havent tested the ecu side yet its still to hot under there and my book sucks so while i wait can somebody tell me how to go about checking the ecu side of the clip....thanks

and the car seems to run a little better with the 92-93 accord o2 sensor in there and all the ones i pulled from the yard looked much better (less carbon or whatever gets on there) than the one that came out of the car would that be the reason????.

Your test result suggests a wiring fault in the harness between the O2 sensor connector and ECU. You will have to disconnect ECU from harness inside pax compartment (a PIA).

W/ ECU harness disconnected again check resistance across pins of the ECU connector. If you get same result as the previous test at the O2 sensor connector, ECU is likely fault.

If you get an open indication or dead short, then more diagnostics to locate the fault.

Test the two wires for shorting to body ground first. Then, sequentially short each wire to ground at the O2 sensor harness side connector and check for ground at the ECU harness end.

If one shows grounded to body or open, you'll have to find and repair the short/break in the wire. O2 sensor connector is a likely faulty location.

If you're convinced wiring harness is good, then ECU is at fault and will need to be replaced. Check for used ECU's from car-part.com near your zip code.

good luck

Ok Brandon, you have a bunch of very good info so far. I'm just gonna break it down in small steps, following my book - it's for a 99 but the procedure is the same:
1. disconnect o2 sensor and grab the conector from harness side, should be male, and look at it - make sure the key is at the top (key is the protusion where the lock tab catches). The bottom 2 pins should be the heater circuit.
2. put meter on ohms (remember the omega sign), low scale or auto range - and measure between left pin and ground (car body or battery negative). You shoud read zero ohms. If you do not you need to follow that wire to the ECM connector, I'll get to that later. If you read zero move on.
3. put meter on volts dc (shows a V and a under-dash on the meter scale). To make sure you have it right measure the battery, should see 12v w/engine off. Start engine. Grab the connector and measure between the right pin this time and ground. It should read 14v or so. If you do not let us know. Looks like there is a fuse that powers that and the cruise control in my book, I'm looking into it.
Depending on what you get with these, we'll follow up with a specific guide, so let us know.

Just to be sure, check all the grounds. I would add another one just to be sure, moving all that around maybe one didn't get put back tight enough.

When you do the checks that draser says, the ignition key should be turned to ON, but the engine not started.

To add to Texas's note, only one of those heater wires goes to the ECU. The pin that should have battery voltage simply comes from the main relay, it doesn't go to the ECU at all. Only the ground side of the heater circuit actually goes to the ECU.

Jim, on mine I have a 15A fuse on driver's side dash fuse box, circ. #6 that sends power to the o2s, is that true for the '94?? - could not find that info.

Never had a 94, so I'm not sure, but yes it should be fused. Regardless of the fuse, I'm pretty sure the hot side of the heater circuit is switched somehow. And when the ECU itself is not energized the ground side of that circuit probably goes to open. So my real point is just that your checks will only work with the key ON.

Brandon, the fault troubleshooting procedure for your 94 is at this link - thank you desert -

http://hondatech.info/downloads/Auto/Manuals

the manual is AboVE Honda Accord 1994 Zip, 44.74 meg, takes a while to download. Look at page 11-34 under Fuel and Emissions.