Hi, my gf has a '99 Accord LX 2.3L sedan with a rough idle (especially when turning the wheel at a stop) and a P01167 CEL code that comes back within one drive after resetting it.

What could it be? I have read that it could be an O2 sensor, but I'm thinking it could be more simple like a clogged up throttle body. My gf also says that the gas pedal sometimes seems to "stick" in the mornings.

What do you guys think it is?

 

Both. The 1167 points to the AF sensor heater malfunction-test then replace.

Have you or when was the last time you gave the TB a good cleaning? TB cleaner, an old tooth brush and a few rags and go at it. Make sure to get both sides of the buttery fly.

Then, when was the last time it had a tune up? Rough idle while the engine is under load (turning the wheel) can come from a few things.

 

The car has never had a tune up as far as I know (it's not my car!). It has about 87k miles. The TB has never been cleaned.

What is an AF sensor heater malfunction? The air flow (oxygen) sensor is not heating up fast enough or something? What are possible causes?

 

The P1167 points to air/fuel ratio sensor - O2 sensor but not quite the same IMO. Without testing I can't say what it is or is not doing...sorry...but the ECU has detected that something is "out of range".

Not sure of the schedule for maint on this model, refer to owners manual, but if it is due then start there...hate to ruin a new sensor because the plugs are not firing correctly and leaving too much gas in the exhaust...or worse, burn up the cat.

 

Well, I ended up cleaning the throttle body and spraying some throttle body cleaner in the IACV. After hooking everything back up, the idle, which was merely kind of low/uneven before is now surging wildly between 1000 and 2000-2500 rpm on a steady rhythm. Also seems like the car wants to take off when it's in gear (drive) as if I were driving a Toyota! What the heck is going on here?

I was hoping the cleaning fluid would just evaporate but I've driven the car around for over an hour, it seems as though the problem has not gotten any better.

 

Any idea? I cannot drive the car like this.

 

With a surging idle like that, it sounds like a vacuum leak. check to make sure all the vacuum lines are plugged back in and in good condition.

 

It does sound like a vacuum leak, but everything is hooked up properly. I took it to a shop and he thought I screwed up the IACV, but I don't think that is the case. I suppose it could be, but I don't want to throw lots of money at it unless I have to. (Then again, the cost of these Honda repairs is minuscule compared to my Jag's!)

 

When you pulled/cleaned the IACV, did you loose any coolant?

 

I NEED HELP!

I took off the throttle body again, and then proceeded to dig deeper by removing whatever the hell that big metal piece is behind the throttle body. I guess this is what the IACV is attached to (intake manifold, perhaps?). It's a little dirty inside but isn't anything that I would think would cause any problems.

Hopefully I can remember how to put everything back. I ended up damaging a hose and will need to replace it (I think it's a coolant hose, maybe an air hose).

What I noticed was that if I unplug the plug that connects to the side of the throttle body (blue), the engine idles smoothly, but high (2000 rpms). If I plug that in and run it without the throttle body plugged in (on top) the engine idles at a normal level (albeit a little rough) and doesn't fluctuate. However, if I plug in the blue connection (side of the throttle body) it fluctuates up and down, although at a lower set of RPMs.

Does this provide any hints as to what it might be? Please help because I am at wits end.

 

Thanks, yes I did lose coolant. I tried bleeding the engine coolant using the bleeder screw, but this did not help the idling problem.

By the way! HINT! The car was completely cool when I started it today and there was no idling problem--for about 45 seconds. Then the problem began as normal. So it would make me believe that it only happens when the car is hot, which it tends to be... all the time.

 

Set the heat to max and try again. Then, sorry just re-read this, how about you think about getting the cade taken care of. That might resolve some issues. Then you will know if it it is the coolant, IACV, ect or the ECU trying to adjust fuel trims.

 

How do I resolve the P01667 code? Where is the AF sensor heater?

 

OK, just following up. I cleaned the IACV and reassembled everything and bled the coolant, now the car runs fine, much better than before. Still waiting to see if the check engine light comes on.

Idle is rock solid now!

 

Part of it is built into the sensor. The ecu then measures other parts. So testing the output from the sensor and the inputs at the ECU help you confirm what is bad.....9 of of 10 the sensor needs to be replaced.

 

What sensor are you talking about? What is the name of the air/fuel ratio sensor, and where is it?

 

Also what is the cheapest place to get it? Thanks for your help!

 

Damn it! Started the car this morning and it's doing exactly the same thing it was doing before. What the heck is going on?

 

Ok it is late, which means I did re-read all of this.

When you bleed the coolant, was the heat set to max?

The A/F can sometimes be confused with an O2 sensor. Since the code states A/F sensor I'm wondering if this is an ULEV car? I can't remember who the OE suplier is right now, I think it was Bosch or Denso - anyone help me out here? -. Again the main thing is to be sure if this is or is not an ULEV car or not....see #9 in the pic.

 

Yup, the engine says "ULEV" on it. Not sure if it's federal or CA emissions, though.

Thanks for all your help. Do you have a part number I can use?

 

Also is there an online vendor recommended by the forums?

 

Nevermind, found it at Majestic Honda. 36531-PAA-L23 for $141.90. Thanks for your help, hopefully this will solve the problem.

 

http://shop.advanceautoparts.com/web...1685954921____

Any idea if that is the same part?

 

Another follow up, it seems as though the car is not doing the crazy idle anymore. It did it yesterday morning, and then it didn't do it for the evening commute (2 miles) and didn't do it for the morning commute today. We replaced the O2 A/F ratio sensor last night and cleared the CEL for P1167, so we'll see if that comes back.

I used the Advance Auto Parts Desnso A/F sensor above.