J R

Hi everyone. I thought that I would get some opinions on my situation. I have about 31,000 miles on my '00 model and recently it began to miss. At first I was not able to tell when it was missing and the problem was intermittent. However, as it got steadily worse, I found that if I was below VTEC engagement at a stable speed I couldn't feel any misfire, but if I went above VTEC, even at a steady speed the misfire became very pronounced.

I don't think that the problem has to do with the VTEC solenoid. If this was the case I think the car would just remain in normal mode and VTEC wouldn't engage. My best guess is that I have one or more plugs breaking down at higher RPMs or that I have some type of problem with the O2 sensor. The last guess is because when I left the car idling for about five minutes and then took it back out to check the miss, it ran almost flawlessly. I have checked the plugs for tightness. By the way, at no time has the car thrown ANY code on the misfires.

Do any of you have any other suggestions for checking this puzzler out? If so, I would sure like to hear your input. The people on this board include some amazingly well versed mechanics and I don't do much of this type of thing anymore.

CG

Sounds like the MAP sensor to me.

marcucci

Any fuel, ignition, or detonation problem will become MUCH more pronounced in VTEC.

It should not be detonation unless you have a faulty knock sensor, in which case you should get a check engine light (MIL). As for the O2 sensor, they generally fail rich or lean which should cause an MIL in itself (the ECU won't tolerate much). They typically fail rich, resulting in dark exhaust or VERY sooty tailpipes. Your plugs would also show fouling.

Have you actually checked the plugs themselves? Though platinum plugs are "good for 100k miles," they rarely last that under agressive or high-RPM driving. You may pull them and check the gap, it could be something as simple as that. I would still suspect a MIL for the knock sensor, but you might be squeaking by.

Your best bet is to take it to the dealer, you should still be under warranty. Even without an MIL, they should be able to reproduce the event and monitor it via the OBD2 datalink.

cdelena

Yup, I went through the same and it was the MAP sensor.

Pinky

Don't you just love this board and the Internet sometimes?! Got a question........the correct answer or a knowlegable possible answer is right there.

Utah S2K

Give the old MAP sensor a check as others have stated. It is located in the inlet pipe between the airbox and the manifold (drivers side)....it's easy to find. Try tapping it with the butt of a screwdriver.......

RT

Bob, the MAP sensor is attached to the throttle body.