2000 odyssey 0170,0172,1491, & 030x codes?

Question

This has been going on for a long time. now have 107,000 miles
The DTCs are normally P0172 “system too rich (bank 1)” (one causing freeze frame) and P0170 “Fuel trim (bank 1)” and sometimes 1491 “EGR valve lift sensor insufficient flow detected” If I let it go long enough I start getting codes P0300-04-05-06 “misfires detected”

When DTCs are set, both the check engine and TCS light come on. I don’t know what the TCS light has to do with it. I can usually predict when it is going to come on by the feel of a 3rd to 4th gear shift (or 4th to OD). I don’t think it is a tranny issue but the engine seems to be causing a slightly rough shift or jerk. When I drive 50-70 MPH on the highway the codes reset and don't come back on till I do some slow driving.

The engine does not run as smooth as it did 25-50k miles ago. I couldn’t hear or feel it running then. It’s almost like the engine mount auto damper isn’t working. But other than that it runs fine. I have run some injector cleaner thru it a

Answer 1

Here's what's going on with your two separate problems.
the P0172 means what it says; that on bank 1 of the V-6 the fuel mixture is too rich and that (P0170) the Powertrain Control Module has tried to adjust for that by commanding a leaner mixture (shorter injection duration) to the point where it cannot lean the mixture out enough to compensate for the problem. The car runs "fine" because its overly rich and loving it.

For problem number 1 then, you need to find out why the mixture for bank #1 is too rich. The probable cause is that you have a leaking fuel injector or an ignition coil for one cylinder that is weak or breaking down. I can't tell you which one it is (injector or ignition coil) it is but you can test for the injector leak using a fuel pressure gauge hooked up in-line with the fuel system. The system should run at about 45 psi and hold that pressure for about 5 minutes after the car is shut off. If the fuel pressure drops (it usually won't take long to do so) then you have a leaking injector. There's a whole list of cautions for doing this test so if you've never done it, pay someone who knows what they are doing to run the test for you to test for the injector. The probability is high that a bad coil or leaking injector is the cause because the condition is only affecting one bank of cylinders; other causes, such as restricted air filters or too high a fuel pressure would affect all cylinders equally.

The P1491 EGR insufficient lift is a product problem with that vehicle and has to do with carbon build up on the egr passage that is preventing the flow of spent exhaust gasses through the Exhaust Gas Recirculation System. Honda has a repair kit that includes a new EGR valve and an EGR tube that will fix that problem. Basically, the EGR isn't working because the flow of gas into the engine is blocked by carbon deposits. Honda did extend the warranty on that part but your car is beyond the terms of the warranty extension. Still, you may what to talk with your Honda dealer to see if you can get honda to pay for it as "goodwilll".

The misfire codes (P03xx) can be related to the EGR valve or the misfire can be caused by the overly rich mixture. Its somewhat confusing as the cylinders indicated by the 0304 (cylinder 4) 0305 (cyl 5) and 0306 (cyl 6) indicate misfires on two separate banks. EGR affects both banks, so it is probably due to that.

As for the TCS light coming on, the way that the Traction Control System works is that if the wheel speed sensors detect one drive wheel spinning much faster than the other it determines that the wheel is slipping and it cuts out cylinders in the engine to reduce engine torque and restore traction. The TCS system is seeing that the engine cylinders are cutting out (misfires) and is 'fooled' into thinking the car is in TCS mode so it puts the light on. The TCS light then is just a confirmation of an engine misfire.

so, what do I think is going on? First the EGR needs to be replaced for the P1491. That may fix the misfires and there is an outside chance it may be responsible for the overly rich condition as a functioning EGR valve will lean out the fuel mixture and one that doesn't work will cause the mixture to be overly rich. So, start with the EGR replacement through Honda (of course, ask them to pay for it!)

The EGR will probably fix the TCS light "problem" as well.

i am bothered by the rich fuel condition on one bank only; I think it is probably an ignition coil breaking down rather than a leaking fuel injector. there is the outside chance it could be EGR. So, after replacing the EGR valve, clear the codes and see if the problem recurs. if it does, then go forward with the diagnosis of the ignition coils and the fuel injector. if the problem goes away after the EGR is replaced, you're home free.

hope that helps

Answer 2

I'm surprised the total bill is almost $8,000; my total bill came out to just over $4200 and Honda paid for all but $800 of it. Then again, this was also back in 2004 when the vans were newer. At this stage, I would probably just junk the car and start looking for a new minivan; the deals out there right now on the Odyssey and Sienna are extremely good. Plus, even if you fixed the car and then tried to trade it in, you'd probably only get at most $5,000-$6,000 in trade. It's just not worth it.