2001 Accord sluggish

Hi folks,

I've got a 2001 Accord EX 4 cylinder, manual trans. 160,000 km on it.
For maybe the past year it's had a hesitation and sluggish feel at times.
I've replaced the plugs, wires, cap and rotor, and used a few bottles of
STP injector cleaner, as well as having had Terraclean done on it. After
having done all of those things, it seems a fair bit more responsive, but
there are still times when it will just bog, or miss for a second, when I
step into the throttle. Usually mostly in the lower revs ( < 2500)

In the process of tuning up / trying to improve the situation, I bought a
Denso O2 sensor from eBay last spring. It's not *the* factory part, but I
suspect it's a universal that was adapted to connect to the factory
harness. The day I installed it, I went for an afternoon drive, and
fairly quickly noticed much improved response from the car. At all revs,
whenever I stepped into the throttle even slightly, it responded instantly
and eagerly. After a couple of days though, it started to occasionally
feel sluggish again, and finally seemed to be more or less back to the way
it was.

Since then I have been through the injector cleanings and new plugs, and
it does feel a little better, but defintely not like it did that day.

I've been on a couple of trips back and forth between Montreal and Halifax
(about 12 hrs) in the last few months, and both times, toward the end of
the day, I've noticed that it was much more responsive, with the same
eager response when I lean into the throttle.

I saved some logs from my Autotap OBD2 scanner which I can provide if it
might help.. I specifically looked at the O2 sensor voltages, which from
what I understand, seem to be more or less correct. It's cycling from
almost 0v to .9v about once a second at idle, and faster at 2000 rpm,
although occasionally it does hang at the high end of the scale, and after
coming down to idle from higher revs, it hangs at near 0v for five or ten
seconds.

My long term fuel trim is around -10%, short term is varying around the
same value.

Anyone have any suggestions what to try next? The car is by no means
running terribly, but I feel like it should be a little sharper than it
is.

Thanks in advance.

 

Manual trans EX? Rare as hens teeth down here in the lower 48.

If it were an auto, I'd suspect the tranny and suggest changing the
fluids, but with a manual ... when my various Hondas have bogged as
you describe, that's what I did, and it worked, but they were all
auto. I'd *thought* it the computer, but I don't know what the 2001
has for a computer - maybe your different O2 sensor causes the
computer to re-train?

J.

 

meant to say, I'd though for a long time it was the computer so did
nothing, thinking it an intentional attempt to save gas by avoiding
sharp acceleration. then it turned out NOT to be that at all.

J.

 

Lots of the EX coupes around up here, can't speak as to whether
they're mostly manuals though.. In any case I'm glad to have the
manual

Well, that's what I thought -- maybe before I swapped the sensors, the
long term trim was fairly far one side or the other, and then when it
started using that value based on the feedback from the new sensor the
resulting mixture was more lean or rich than normal until it balanced
out... which could mean that there is something else causing it to be
running too lean or rich... I wish I'd thought to pull the data on
the old sensor before I replaced it, to see where the long term trim
was then...