My son has a 2001 HOnda Passport that has a nasty habit of running real rough every once in a while.  The check engine light used to come on but no longer does when the engine decides to do its thing.  It sometimes does not like to idle and then when started will be real rough running on acceleration but smooth out when at speed and not under pull.  Back when the check engine light would come on there were too many codes for the Auto Zone tech to decipher what was happening.  We changed the plugs, fuel filter and air filter and that seemed to take care of the problem for a little while, but lately it has started occurring again.  Any ideas on what to do?

______________

finally arrived and rarin' to ride 
- SAVE THE WAVE -

   

[QUOTE=BT_Jett] Back when the check engine light would come on there were too many codes for the Auto Zone tech to decipher what was happening. 
[/QUOTE]

Take it back and have them pull the codes, and ask them to not try to decipher them, just print them out...
The codes will help determine a starting point. Get the codes(if any) and post them here, or you can P/M me, and we'll "decipher" them ourselves...
When you changed the plugs, how were the wires?
There are a LOT of things that can cause this, and Ken might have better insight on narrowing down the trouble, but codes will certainly help...

______________

Joel Adams
C3VR Lifetime Member #56    
My Link


(click for Texas-sized view!)             NCRS

"Money can't buy happiness -- but somehow it's more comforting to cry in a CORVETTE than in a Kia"

Will do -- take a day or two -- the son and car are out and about

______________

finally arrived and rarin' to ride 
- SAVE THE WAVE -

   

Can't get the codes -- the tech (?) cleared them out when he read and the car has not registered anymore codes.  However, it still on occasion does the bucking on acceleration and dying at a stoplight. 

______________

finally arrived and rarin' to ride 
- SAVE THE WAVE -

   

Wow...so many things can cause it...where to start?
Without the codes, or data info, I can only guess.
Could be:
Temp Sensor
MAP sensor
Ign. Coil/Crank sensor issue
TPS(throttle position sensor)
EGR malfunction(Honda has had a TON of troubles with their EGR systems)
Injector wiring(as the engine moves under load, it stresses the wiring harness)
Alternator problem(yep...it's computer controlled, and a malfunction in that system can skew reference voltages to any/all of the engine sensor).

Kinda flyin blind here!
I'll check tomorrow for any TSBs from Honda, and see if I can come up with something to narrow down the possibilities...no guarantees, but I'll see what I can find.


______________

Joel Adams
C3VR Lifetime Member #56    
My Link


(click for Texas-sized view!)             NCRS

"Money can't buy happiness -- but somehow it's more comforting to cry in a CORVETTE than in a Kia"

I sent ya an e-mail, Bob...

______________

Joel Adams
C3VR Lifetime Member #56    
My Link


(click for Texas-sized view!)             NCRS

"Money can't buy happiness -- but somehow it's more comforting to cry in a CORVETTE than in a Kia"

Unfortunately my system has been acting up and finally crashed.  We are back on line for a little while -- the laptop is working hard at trying to provide services.  Anyway -- I did not get your email, can you resend?

______________

finally arrived and rarin' to ride 
- SAVE THE WAVE -

   

I'll sure do it, Bob!

______________

Joel Adams
C3VR Lifetime Member #56    
My Link


(click for Texas-sized view!)             NCRS

"Money can't buy happiness -- but somehow it's more comforting to cry in a CORVETTE than in a Kia"

It's back but this time we got the codes --PO172 and P0171.  I pulled the MAF sensor and cleaned but no improvement.  Any ideas are welcome.

______________

finally arrived and rarin' to ride 
- SAVE THE WAVE -

   

Well, now we're gettin somewhere...let's jump up on da sidewalk and take a look. Those appear to be O2 sensor codes, but I'm not sure. I'll check once I get to the shop...stay tuned....

______________

Joel Adams
C3VR Lifetime Member #56    
My Link


(click for Texas-sized view!)             NCRS

"Money can't buy happiness -- but somehow it's more comforting to cry in a CORVETTE than in a Kia"

P0171 = Bank 1 system too lean
P0172 = Bank 1 system too rich
Kinda a contradiction, eh? These have to do with the 02 sensor readings. Bank 1 is usually the side that has the #1 spark plug...whichever side that is. ON your vehicle, it will be the right side(looking from the front of the engine).
The codes are telling us that the readings the sensor is getting is erratic, showing it too lean at one point, and too rich at another time. This doesn't necessarily mean there is a problem with the 02 sensor(s), but that the PCM is seeing readings that are not consistent with what it expects to see.
If the reading is showing a lean condition, the PCM will command more fuel...if it shows a rich condition, the PCM will command less fuel.
Check for vacuum leaks, the PCV valve, and around the EGR valve for leaks. Bad/questionable fuel can also cause these codes. One or more fuel infectors that are not operating properly can also do it, as can a faulty MAF sensor. Even a leak in the exhaust can set these codes.
The diagnostic chart is fairly involved, and requires being able to access engine data on a scam tool...might be time to take this to a qualified shop for diagnostics, and repair. First check it really well for vacuum leaks, and exhaust leaks, especially around where the pipe bolts up to the manifold.

hth


______________

Joel Adams
C3VR Lifetime Member #56    
My Link


(click for Texas-sized view!)             NCRS

"Money can't buy happiness -- but somehow it's more comforting to cry in a CORVETTE than in a Kia"

thanks for the info -- Time to look for leaks, especially before the snow flies this weekend.

______________

finally arrived and rarin' to ride 
- SAVE THE WAVE -

   

Did you find a fix for this yet..if not pull off the EGR valve and clean it out..these codes together point to it..its been a while since I worked at Honda so I don't remember if this EGR is electric or vacuum..if it is a vacuum style push up in it and see if it holds vacuum by holding your finger over the port..it shouldn't move..if it doesn't spray carb cleaner in and on the pintle..maybe pick at it with a small pick tool..watch that crappy gasket they use..it falls apart and you may not be able to re use it..make sure the pipe on the intake is clear that it bolts to..when you put it back on if it idles rough rev the engine to clear it out..if it doesn't you just found the problem..replace the EGR valve..
Rich

______________

My first parade at Carlisle 2010