Mechanics

VEHICLE SHAKES AT SPEED

2001 Honda Odyssey

Shakes or Wobbles problem
2001 Honda Odyssey 6 cyl Front Wheel Drive 141000 miles

My minivan shakes when on the freeway going over 50 mph. If I back off the accelerator the vehicle rolls smoothly. No vibration comes up through the steering wheel, it appears to come from the engine. I have changed the ERG valve. The car has never had a tune up. Check engine light is on. On occasion the TCS light comes on. Had transmission rebuilt about 6 months ago. TCS light problem was happening before trans was rebuilt. I purchased the car used (with 40K on the odometer) I asked the local honda dealer if the EGR fix had been performed (installation of a tube in the intake manifold) they told me it had already been done on my vehicle.
Any suggestions?
Avatar
Shotgun1958
March 29, 2009.




Let's start by checking the check engine light. Take the vehicle to Autozone and have them scan the computer for free. Post the code NUMBER(S) here. It would also help if you perform the required tuneup. 140K miles is a long time without proper maintenance.

Tiny
Zackman
Mar 29, 2009.
Good idea, BUT- I can't find any info on performing the tune up except changing the spark plugs! I've searched the internet for over an hour and looked in my Chilton's manual. Spark plugs, air filter - that's about it.
Suggestions?

Tiny
Shotgun1958
Mar 29, 2009.
While that is true (to some degree), spark plug is the only ignition part to replace. You still should replace your PCV valve, clean the throttle body of carbon build-up, add some fuel injector cleaner into the gas tank, replace the cabin air filter and


http://www.2carpros.com/forum/automotive_pictures/55316_01odesseytuneup_1.jpg



You still need to go to Autozone for the scan for the check engine light.
AD

Tiny
Zackman
Mar 30, 2009.
Got two codes
Po420 - Catalyst Efficiency below threshold, bank 1 and
Po401 - EGR Flow insufficient.

I just replaced the EGR valve about a week ago.
I" m putting in new plugs this afternoon.
It shakes only under load, ie, up hills or during acceleration. Sometimes the TCS light is on, sometimes it's not.
RPMs don't seem to matter. 2,000 rpm at 65 up a slight hill and it shakes. 2,000 in D3 going about 45 up a hill and no shake.
Could it be the transaxles? Had balancing and alignment done last week.
ALSO - called local Honda dealer and the assured me that the EGR " pipe fix" had been completed on my car, although they could not tell me when.
Very confusing.

Tiny
Shotgun1958
Apr 5, 2009.
MIL IS ON WITH DTC P0420
TECHNICAL SERVICE BULLETIN

The MIL is on, and DTC P0420 (catalyst system efficiency below threshold) is stored.

PROBABLE CAUSE
The catalytic converter has deteriorated.
CORRECTIVE ACTION
Replace the catalytic converter, and check for any related DTCs.
PARTS INFORMATION
Catalytic Converter: Odyssey (all): P/N 18160-P8F-J00, H/C 6148746

As for P0401, you may wish to call a different dealership and ask them the same question. While reading the TSB, I noticed that even if the repairs were completed, there is a chance that the pipe is clogged, causing EGR insufficient flow.

Tiny
Zackman
Apr 5, 2009.
Would a bad catalytic converter cause the shaking? Why?

Tiny
Shotgun1958
Apr 6, 2009.
Usually bad cat is plugged up. As such, the exhaust gas has nowhere to go but back into the engine, creating enormous amount of negative pressure in the system. Because of this, your engine will lose power battling the pressure and as a result you will feel the shaking.

Tiny
Zackman
Apr 7, 2009.
That's it! Took it to the dealer and had the intake removed and a passageway unplugged. It's a fairly common problem with these cars.
Thanks for your help!

Tiny
Shotgun1958
Apr 18, 2009.
I spoke to soon! The problem is not fixed. My odyssey still shakes above 40 mph, but only after it has been running more than 20 minutes or so. If it is shaking and I back off the gas a bit and then get back on the gas, there is no shaking for 5 to 10 second, then it shakes again. If I'm not on the gas or going down hill, no problem. Only when the engine is under a load. Cat problem? If so, how easy is it to change myself? Someone mentioned that it might be a clogged air filter. What do you think?
Thanks in advance!
BTW - after the clogged intake manifold was fixed they turned off the check engine light. I has not come back on.

Tiny
Shotgun1958
Apr 19, 2009.

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