1999 does not have an FITV.
#9 in the picture is the IACV.
The big part in the middle with no number is the plenum of the intake manifold.

 

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!

The whole job took probably about 4 hours total, including disassembly, cleaning, and assembly, bleeding coolant, etc.

 

Thanks for the diagram.

The problem has come back just as bad as before. I am beginning to wonder if this is a problem with the primary O2 sensor on the exhaust manifold. Isn't that what the P1167 code is indicating? Could a faulty O2 sensor on the exhaust manifold cause problems like this?

FYI this is a ULEV engine, I don't know if that makes a difference.

 

When I had a 6th-gen, it wasn't ULEV, so I didn't save the codes that are unique to the ULEV engine. I'll take your word for P1167 being the O2 sensor. Is it the heater or the actual sensor reading? If the problem causes the engine to run lean, it might add to the idle problem.

ULEV does make a difference in which O2 sensor you buy; the front sensor IS a different sensor so be sure you buy from someplace that actually lists a different part for ULEV & non-ULEV engines.

How to deal with surging idle is pretty much the same for the ULEV engine. That particular parts picture (throttlebody) is the same for the ULEV engine.

Check out this thread about setting the base idle & forcing your car to re-learn the idle control.
https://www.hondaaccordforum.com/for...e-speed-38734/

 

I forgot again, not sure if you saw my other post. Now I see you did bleed with the heat set to max. I also posted about the same as Jim (ULEV vs LEV) about the sensor and it's location.

 

Yup, what I did for the bleed procedure was:

1. With engine off, remove radiator cap
2. Loosen bleeder screw
3. Fill radiator with coolant until no bubbles come out of bleeder
4. Tighten bleeder screw
5. Start engine with radiator cap still off, heat set to max and on hi fan speed
6. When coolant starts gushing out the top of radiator, replace radiator cap

 

And yes, I now know where the location is (right on top of the exhaust header). Does anyone know the part number for a '99 LX 2.3L ULEV engine A/F sensor? (I assume that includes a new heater?)

 

Advance Auto Parts: Air-Fuel Ratio Sensor by Denso - Part 234-9025

Any idea if that is the same part? Advance is having a killer deal right now...

 

May not make a hill of beans, setting the heat to max hould be done as step one, according to the info I have.

First, are you "sure" this is an ULEV car? Is it on the valve cover (? maybe that is the newer ones). What is the stamping on the engine block?

If so, I did not double check your search, Denso is a trusted brand IMO....go for it. If you go to the store, see if they can look it up by the VIN, another member may be able to tell you, remind me, what digit of the VIN confirms an ULEV vs a LEV.

Please don't take any of my comments the wrong way. I and many others really do want to help.

 

Yup it's on the valve cover. I won't take offense at any comments, I realize you are just trying to get the right info out of me so you can help me!!!

Interesting, I wonder whether setting heat to max when the car is off makes any difference. Actually that makes sense, because if heat is not set to max, you aren't letting coolant flow through the heater core?