Schnitzer

Hi all,

I've got a Honda Accord 1998 V6L with 198,000 kms on it. The car has been running absolutely fine until last month when the CEL came on for the first time.

I took the car out after 3 days of no use. I was driving (coming to a stop) at the time the CEL came on and the car then started shaking and the idling RPM dropped down to around 400 instead of the normal 800. The gear changes became jerky all of a sudden. Also felt a loss of power when start from a dead stop. Drove the car for 10 kms, then shut/start the engine and the light was gone. Idling was normal, no weird engine sound all good. Ever since that, I was driving regularly and the issue never reappeared.

Then I left the car again for 10 days when I was overseas. On my return, as soon as I started the engine, CEL came on, idling RPM came to 400 and car started shaking and vibrating just like before along with jerky gear shifts. Again saw a loss of power and the car struggled to get moving from a stop. But after driving the car for a day, the issue didn't appear again for about a week.

Since the car was due for a minor service (including engine oil, oil/air filter) I got that done right away thinking that maybe the cause . Next day after service, the CEL issue got worse. Now every morning when I start the car, the CEL is on, and same symptoms appear. The issue disappears after I drive the car for 15-30 mins then stop/start the engine, but unlike before, it comes up again the next morning .

Can anyone share their knowledge and experience with this issue? My friend say it might be Oxygen Sensor, another friend says it maybe the knock sensor. But I'm curious as to why did the issue got worse after the service (oil and filter change)?

PS: I've put in Castrol 10w-40.

Thanks in advance!

holmesnmanny

Wouldnt it make sense that you should need to pull the check engine code when it illuminates ?

Do that and report back what the code is.

Schnitzer

Hey,

I took it to the mech for a scan, but they came up with the excuse saying it's a US Import (I'm in Australia), so he can't read the engine codes...

MAD_MIKE

On Honda OBDII cars there are three ways to get the codes.
1. OBDII scanner/code reader.
2. Blue two wire diagnostic connector, usually under the glove box, above the passenger kick panel, above edge of carpet in foot well, or behind the center console near the firewall.
3. Jumping terminals 4 & 9 on OBDII connector.


The latter two will net you OBDI codes through the CEL light. The codes will not be as descriptive as OBDII but it should get you pointed in the right direction.

Schnitzer

Hey Mike,

Thanks for the response. I shorted the blue two-wire diagnostic connector using a paper clip, and followed the procedure. The CEL blink that I got was:

Zero Long blinks, 3 short blinks. The code kept repeating so I believe its just one code. Is this code 03? Any idea what this means?

Schnitzer

Thoughts anyone

MAD_MIKE

3 MAP - manifold absolute pressure sensor
Without the MAP sensor the engine will be as you described.

Since our cars are Speed Density systems it is only 'guessing' rather than measuring actual air flow like on a Mass Air Flow car.

If there was recent work done on the car, verify that the wire harness to the MAP was not damaged or the connector has not come loose. Or any part of the intake manifold from throttle body to head is loose or damaged.

Ideally you would want to remove the MAP sensor, leave it connected to the wire harness, turn the ignition to ON and while monitoring voltage output with a voltmeter, apply vacuum(using a vacuum pump) to the MAP and watch for the voltage output signal to change.

Found this video, it has a simple diagnostic procedure. Also note that he said make sure it is the sensor as a leaking or cracked manifold may cause the MAP to read incorrectly...

Schnitzer

That's real good stuff - Thanks Mike!

The symptoms I have conform to the symptoms with MAP issues.

Since the CEL comes intermittently and isn't always on, would it be safe to suggest that my MAP is not completely dead and is working sometimes?

If it isn't a goner, then would it be safe to continue driving or is this something that require immediate attention?

Also, since I don't have the tools, is this something for a mechanic or for an electrician?

Cheers mate!

holmesnmanny

No, it's really not safe to drive like that. I would first just check the connector, perhaps it's not connected all the way or perhaps a wire is loose or partially broken.

A map sensor replacement really is one of the easiest things to replace and for your car it's one of the easiest things to replace.

It sits right on top of the throttle body and has two bolts holding it down.

http://www.hondapartscheap.com/auto-...er=37830paas00

One thing you need to do though because sometimes it's actually the ecu that's bad. Is to just do one simple test. You will need a multimeter. You can get an "autoranging" multimeter from Walmart and it will be very useful for its mere $20 you will buy it for.

Set it on DC voltage and to the 20 volts setting.

Turn the ignition to on without starting the car. The dash lights will turn on.

Disconnect your existing map sensor connector(it is part 11 in the above illustration) and probe each pin of the connector starting with the middle one until you get voltage. It should be about 5 volts. Two of the pins will not have any voltage.

If you do not get voltage on any of the pins then it's likely the ecu is bad. If you get voltage, then I would get another map sensor.

Schnitzer

Hey Holmesmanny,

Thanks for the tip. The CEL is gone for now, hasn't come up for last 2 days and I've continued driving. Should I touch the map sensors or the connecting wires or should I leave it for when the CEL comes on again?

Also, another startling discovery I made is that my car now seems to be REV Limited to 5000 RPM. What's going on !!! I don't wanna sell my car

MAD_MIKE

Not sure with J series engines. But it may be some form of limp mode and is only going off preprogramed tables.

If the MAP code popped up, test it. If the voltage to vacuum is fubar'd then replace the sensor.

holmesnmanny

It depends if you want to fix the issue. If you dont want to fix it just leave it alone.

Schnitzer

Update:


Replaced Air filter and cleaned the MAP sensor, didn't help.

Took it to the mechanic, the code reading was still the same P0107 - MAP Sensor.

CEL came on just when I was about to leave the workshop, and the mech looked at it. He says by the sound of it (rattling sound coming from right under the car), it looks like the catalytic converter. He says the honey comb or internal parts are broken and that's whats causing the metallic rattling sound, plus the CEL light as well.

What do you guys think? If it's the catalytic converter (CC), why is the CEL leading us to a different direction? Or are symptoms related is anyway? :S

holmesnmanny

actually he may be right .. since the map sensor works off vacuum if the cat is clogged it could push back vacuum into the intake which could mess with the map sensor readings

have him open up the exhaust at the cat and see if it idles better

MAD_MIKE

Let the car warm up and use a infared temp gun. If the catalyst is the same temp or cooler than the rest of the exhaust then you know the catalyst isn't doing anything.

Schnitzer

Update #2:

Went to an exhaust shop, they checked the catalytic and it was shattered from inside and choked. Got it replaced for $400 for a new metallic catalytic (promising better performance bla bla).

The guy said I need to get a tune up now and the CEL cleared as well. Can I just unplug the battery terminal overnight to clear the CEL? And do I really have to get a tune up done? (am trying to save cash by only doing necessary stuff).

Another question, since the CEL is now steadily ON and not playing hide/seek like before, the transmission has started slipping and am getting a lot of jerky shifts. Are these due to the CEL? Just to let you know, the transmission was rebuilt at 165,000 kms, and the car is now at 199,000 kms.

Any thoughts guys?

MAD_MIKE

If the plugs are worn or the O2s are becoming lazy, you will lose power, economy, and degrade that brand new catalyst.

If your CEL is still on, pull the code. If it is for the MAP sensor again, and you have not tested it, test it.

In the short term you might save a couple of coppers, but in the long term you will cause more wear and tear.

Pull the codes and check the components that come up as faulty.

Schnitzer

Hey Mike,

To reset the CEL code, I disconnected the battery terminals for 15 secs and put them back on again. Started the car and the CEL disappeared to my relief. Kept it running for 5 mins and turned off the car without any issues.

Two hours later, started the car again and the CEL came back on All the same issues still there, except the noisy rattle is gone, and the car seems to have a bit more power. But other than that, the car is still shaking and idling at 400 rpms, with the gear shifts getting quite jerky now Checked the CEL code by shorting the blue 2-pin connector and it was still 0 long, 3 short blinks, aka MAP sensor.

Anyways, took the car out for some grocery (drove 10 mins away), came back in 30 mins, started the car, and no CEL. Everything is fine, and driving like brand-new, no noise, no vibration, idling at 800 rpms, with ideal gear shifts! Nothing wrong at all!

Drove the car another 15 mins, stopped at another place. Came back to the car in 10 mins and the bloody CEL is back on with all the issues!

What do I do

Is my transmission gone? Did I reset the ECU the right way??

MAD_MIKE

Test that MAP sensor when the engine is hot.
Electronic components are funky like that, they may operate fine when cold, but as soon as you get some heat soak into it(like when a car has been off for 5-10min) the sensor may be bad.

Check that there are no vacuum leaks, use MAF sensor cleaner/Carb clearner around the major gaskets and joints of the intake after the throttle body. If there is no change in idle quality, then I would suspect the MAF is SNAFU/FUBAR. Test it when the engine is hot like in that YT video and albeit you will get some funky readings.

holmesnmanny

You need to have the code cleared with a scanner. Then if it comes back on you need to get a vacuum pump and a multimeter and test the map sensor.

Schnitzer

Hey Mike, I haven't got the kit (as shown in the video) to test the MAP sensor but a friend of mine does so I'll get him to do it for me. Will post the results soon.

Manny, my mech couldn't locate the OBD II port in the car. There's only the blue 2-pin connector, but here, in Australia, none of the 3 mechanics I've been to have the tool to read through the blue connector. Hence I had to resort to the jumping wire method

MAD_MIKE

There are a few connectors on OBDII Hondas.
Two wire is for retrieving codes.
Three wire is OBDI DLC connector. Most people don't even know what that is for.
16Pin OBDII connector. IIRC on your car it should be located above the hood latch under the dash.

http://wikitest.pgmfi.org/twiki/bin/view.pl/Library/DLC

If your mechanic cannot find any of the data links then they are not trying, or you need to located a different mech.

Schnitzer

I went down to look for it myself. All I could see was a bunch of wires, but couldn't locate the 16-pin connector as shown in the pictures in the link. Maybe I couldn't spot, hence I've attached some pics. Can you see anything?

Lost Again

Is this a RHD car?

Schnitzer

Yup RHD. Made by Honda of America, imported by Honda Australia.