Random1

[QUOTE=LATEOTT,Jan 2 2007, 11:51 AM]Thanks for posting the data Random1.

Billman250

Random, you have a lean misfire.

Can be an air leak anywhere after the throttle plate, or a lack of fuel.

It is likely NOT a valve adj issue, compression issue, mechainical issue.

You're also going to need an HC reading before the cat to further narrow it down, but it's not a necessity.

I would start by checking/replacing all the vaccuum lines that control the air pump. Anyone of them can add air after the plate, causing the ECU to add fuel.

Start by ridding the car of the air pump code. Don't focus too much on the cyl1 misfire at this time.

LATEOTT

If I disconnect a vacuum hose the ST fuel trim does not go positive. If anything, the STFT might adjust up a little, such that the average STFT is around -9 rather than -11, but the swings in the data (~ 4%) make it difficult to see subtle changes. It definitely is not going positive. The closest it gets to positive is when I reconnect vacuum and the engine almost stalls--in that case the STFT spikes up to zero for a fraction of a second.

If I reconnect the hose the engine stumbles almost to stall, then recovers.

There is about a 4% swing in the data with peaks about 10 seconds apart--I don't know if thats from something periodic in the engine or just a slow data output from the PBD port.



Now I don't know if that's what you meant by "giving it a leak"...

Since I can't make it go positive at idle, I can't play with vacuum to make it stabilize at zero.

I was not able to record any DTC freeze data in this session, though a P1399 did occur.

LATEOTT

By the way I now have the ProScan software. Thanks for the info.

LATEOTT

Bump for help, if there are any experts out there.

Random1

I cleared the code and it has not come back.

I also got P0171 two times. I forgot to get the FF data on the first one. Below is the FF data for the second one.

Ron

Ok, Sheila's car just developed the P0300-P0304 + P1399 CEL codes with rough idle and missing under load. It's a MY2000. This was sudden onset with no problems on the morning commute and ragged running, once to the point of a blinking CEL, on the way home.

The CEL is now solid so I assume the blinking was during a period when the missing so so severe that, if continued, the catalytic converter would have been damaged.

She has not gotten gas in the last few days, so fuel should have remained constant. It being a day at the office and all, there were no overrevs. Valves have been adjusted and compression checked within the last year.

I looked at the car today and after clearing the CEL watched to see what would come back first. I got 1399 and then 301. Shortly afterwards, 303 and 304 appeared. I'm sure if I had continued running the car with the reader attached 302 would have returned.

I whacked the MAP sensor to no effect. I listened for any vacuum leaks and checked hoses without finding anything amiss. The car hasn't cooled down enough for me to pull the plugs or injectors yet.

Reading the short term fuel trim data it averaged -10.469. Looking at my car (also MY2000 S) I see an average of about -11.7. One interesting thing, the long term trim stayed at 0 the whole time I watched it. I cleared the ECU on my car and it also started reading 0 for long term trim but quickly started to rise as it ran. Does this suggest anything to anyone?

From reading the trouble shooting guide in the manual for these codes, I'm wondering about low fuel pressure followed by clogged injectors. My current plan is to run it by the dealership tomorrow for a fuel pressure check.

Anyone have other ideas?

Thanks!

hotwhlz1

Random I am going through everything you described now - Honda dealer is trying to money pit me big time... Shoot me an email...

kmoor1967@yahoo.com

thanks...

Random1

[QUOTE=Ron,Feb 7 2007, 01:50 PM] Ok, Sheila's car just developed the P0300-P0304 + P1399 CEL codes with rough idle and missing under load.

Random1

How many miles are on your car?

I'd shoot you an email if you will indicate why? Do you have a particular question?