Honda Car Forum

I spent several hundreds dollars to pass emissions last month. I was
receiving eCU codes P0401 and P0420, which were both resolved after
the shop replaced my Catalyst Converter and O2 sensor, but now the
"Check Engine" light is back with the following codes:

0171 and 1456

I knew something was wrong since the car had troubles accelerating
after being at a complete stop. It will jerk and sometimes jump.
I've never seen these two codes before having the shop work on my
car. Could this be just a mere coincidence or should the shop help
fix the problem?

The Catalyst converter was after market.

--tj

techjohnny@gmail.com5/6/08
15:40c5e31108-57f7-4f92-9cb4-10bc4f0518ad@j33g2000pri.googlegroups.com

> I spent several hundreds dollars to pass emissions last month. I was
> receiving eCU codes P0401 and P0420, which were both resolved after
> the shop replaced my Catalyst Converter and O2 sensor, but now the
> "Check Engine" light is back with the following codes:
>
> 0171 and 1456
>
> I knew something was wrong since the car had troubles accelerating
> after being at a complete stop. It will jerk and sometimes jump.
> I've never seen these two codes before having the shop work on my
> car. Could this be just a mere coincidence or should the shop help
> fix the problem?
>
> The Catalyst converter was after market.
>
> --tj
>

Would have been nice to have the year of the vehicle.

0401 code-Sound like the EGR system was acting up before. I assume you have
an EGR system or you wouldn't have gotten the 0401 code. Ask the mechanic
that worked on it if he addressed that issue. Some on this newsgroup think
that a faulty EGR system will cause problems with the cat conv but I can't
confirm or deny that. 0420 is catalytic conv efficiency is low. That should
have been corrected with the new cat.

0171 is fuel system too lean. Could be a LOT of different problems. Plugged
fuel filter. MAP sensor. Primary O2 sensor. Bad fuel-drain tank and refill.
Valve clearance incorrect. Exhaust leakage. Check for air leaks into the
intake manifold. Could be an oxygen sensor problem. A garage with good
diagnostic skills should be able to tell you. Perhaps the group will chime
in on this code with some more ideas.

1456 is a problem with the evap emissions control system. Start by making
sure the gas cap is on tight. Try a known good gas cap on it. After that you
need some trouble shooting skills. There is a solenoid that controls vacuum
to the purge canister to clean out the fuel fumes. Perhaps there is a leak
in that hose and when the solenoid opens it lets in raw air (thus the lean
mix) instead of the expected gas fumes (richer mix). Not much but a place to
start.
--
Pickleman
halfsour@roadyourpantsrunner.com
Please remove "yourpants" to reply
1998 Civic HX MT with 142K
2000 CRV EX MT with 98K

On May 7, 2:50 pm, delbert brecht <halfs...@roadrunner.com> wrote:
> techjoh...@gmail.com5/6/08
> 15:40c5e31108-57f7-4f92-9cb4-10bc4f051...@j33g2000pri.googlegroups.com
>
>
>
> > I spent several hundreds dollars to pass emissions last month. I was
> > receiving eCU codes P0401 and P0420, which were both resolved after
> > the shop replaced my Catalyst Converter and O2 sensor, but now the
> > "Check Engine" light is back with the following codes:
>
> > 0171 and 1456
>
> > I knew something was wrong since the car had troubles accelerating
> > after being at a complete stop. It will jerk and sometimes jump.
> > I've never seen these two codes before having the shop work on my
> > car. Could this be just a mere coincidence or should the shop help
> > fix the problem?
>
> > The Catalyst converter was after market.
>
> > --tj
>
> Would have been nice to have the year of the vehicle.
>
> 0401 code-Sound like the EGR system was acting up before. I assume you have
> an EGR system or you wouldn't have gotten the 0401 code. Ask the mechanic
> that worked on it if he addressed that issue. Some on this newsgroup think
> that a faulty EGR system will cause problems with the cat conv but I can't
> confirm or deny that. 0420 is catalytic conv efficiency is low. That should
> have been corrected with the new cat.
>
> 0171 is fuel system too lean. Could be a LOT of different problems. Plugged
> fuel filter. MAP sensor. Primary O2 sensor. Bad fuel-drain tank and refill.
> Valve clearance incorrect. Exhaust leakage. Check for air leaks into the
> intake manifold. Could be an oxygen sensor problem. A garage with good
> diagnostic skills should be able to tell you. Perhaps the group will chime
> in on this code with some more ideas.
>
> 1456 is a problem with the evap emissions control system. Start by making
> sure the gas cap is on tight. Try a known good gas cap on it. After that you
> need some trouble shooting skills. There is a solenoid that controls vacuum
> to the purge canister to clean out the fuel fumes. Perhaps there is a leak
> in that hose and when the solenoid opens it lets in raw air (thus the lean
> mix) instead of the expected gas fumes (richer mix). Not much but a place to
> start.
> --
> Pickleman
> halfs...@roadyourpantsrunner.com
> Please remove "yourpants" to reply
> 1998 Civic HX MT with 142K
> 2000 CRV EX MT with 98K

Thanks for the feedback. It's a 1998 Honda Accord 4cyl EX with 212K
miles with a recently replace transmission (50K miles ago).

On May 7, 2:50 pm, delbert brecht <halfs...@roadrunner.com> wrote:
> techjoh...@gmail.com5/6/08
> 15:40c5e31108-57f7-4f92-9cb4-10bc4f051...@j33g2000pri.googlegroups.com
>
>
>
> > I spent several hundreds dollars to pass emissions last month. I was
> > receiving eCU codes P0401 and P0420, which were both resolved after
> > the shop replaced my Catalyst Converter and O2 sensor, but now the
> > "Check Engine" light is back with the following codes:
>
> > 0171 and 1456
>
> > I knew something was wrong since the car had troubles accelerating
> > after being at a complete stop. It will jerk and sometimes jump.
> > I've never seen these two codes before having the shop work on my
> > car. Could this be just a mere coincidence or should the shop help
> > fix the problem?
>
> > The Catalyst converter was after market.
>
> > --tj
>
> Would have been nice to have the year of the vehicle.
>
> 0401 code-Sound like the EGR system was acting up before. I assume you have
> an EGR system or you wouldn't have gotten the 0401 code. Ask the mechanic
> that worked on it if he addressed that issue. Some on this newsgroup think
> that a faulty EGR system will cause problems with the cat conv but I can't
> confirm or deny that. 0420 is catalytic conv efficiency is low. That should
> have been corrected with the new cat.
>
> 0171 is fuel system too lean. Could be a LOT of different problems. Plugged
> fuel filter. MAP sensor. Primary O2 sensor. Bad fuel-drain tank and refill.
> Valve clearance incorrect. Exhaust leakage. Check for air leaks into the
> intake manifold. Could be an oxygen sensor problem. A garage with good
> diagnostic skills should be able to tell you. Perhaps the group will chime
> in on this code with some more ideas.
>
> 1456 is a problem with the evap emissions control system. Start by making
> sure the gas cap is on tight. Try a known good gas cap on it. After that you
> need some trouble shooting skills. There is a solenoid that controls vacuum
> to the purge canister to clean out the fuel fumes. Perhaps there is a leak
> in that hose and when the solenoid opens it lets in raw air (thus the lean
> mix) instead of the expected gas fumes (richer mix). Not much but a place to
> start.
> --
> Pickleman
> halfs...@roadyourpantsrunner.com
> Please remove "yourpants" to reply
> 1998 Civic HX MT with 142K
> 2000 CRV EX MT with 98K

Thanks for the feedback. It's a 1998 Honda Accord 4cyl EX with 212K
miles with a recently replace transmission (50K miles ago).

delbert brecht <halfsour@roadrunner.com> wrote in
news:C4479C5C.99D2%halfsour@roadrunner.com:


<snip>




The OP has not said the year of his Accord, as you point out.

There are numerous TSBs involving P0171 and P1456. These are year (and
sometimes engine) specific.

Honda's EVAP systems are notoriously trouble-prone with several known
issues that set a P1456. It turns out that underneath the back of the car
is not the best place to install something as sensitive and finicky as the
currently mandated EVAP system.

To the OP: Please provide year and engine of your Accord. Also state trim
level (EX, LX, Hybrid, etc.)



--
Tegger

The Unofficial Honda/Acura FAQ
www.tegger.com/hondafaq/

On May 6, 3:40 pm, "techjoh...@gmail.com" <techjoh...@gmail.com>
wrote:
> I spent several hundreds dollars to pass emissions last month. I was
> receiving eCU codes P0401 and P0420, which were both resolved after
> the shop replaced my Catalyst Converter and O2 sensor, but now the
> "Check Engine" light is back with the following codes:
>
> 0171 and 1456
>
> I knew something was wrong since the car had troubles accelerating
> after being at a complete stop. It will jerk and sometimes jump.
> I've never seen these two codes before having the shop work on my
> car. Could this be just a mere coincidence or should the shop help
> fix the problem?
>
> The Catalyst converter was after market.
>
> --tj

i suspect that your Accord has on-going leaking injectors problem
leaking injectors will cause the EGR valve, catalytic converter and
EVAP system to fail, and result in poor drivability and bad fuel
economy

inspect and fix the injectors first, a bottle of fuel system cleaner
may do it.

you dont want to buy another cat for the next emission check, yes?