elantra 2001 has no oxygen sensor and it ECU runs in open loopalways!
 

Hi all,
I recently bought an Elantra 2001 model car. When i did the emmission
test, it failed with high CO and HC. CO percentage was in range 5-6.
Its fuel consumption is also very high.

The idle is very smooth, no knocking when accelerating and no other
unusual behavior either.

As the first thing, i replaced all spark plugs, got the distributor
checked and wires checked. They are all fine. Then i did a fuel system
clean and checked whether there are any problems with injectors and
they were fine too.

Today, i got its ECU scanned and it gave the code p0342. I replaced
the camshaft position sensor, but it still gives the same code. In
addition, the reading of oxygen sensor voltage is 0.0V always. When
inspected, we could not find any oxygen sensor! And the engine runs
always in open loop (even after it gets heated!). Now im fully
confused! Please let me know whether there are engines where you don't
have a oxygen sensor? And if there are engines like that, will they
run in open loop always?

thanks in advance!

Re: elantra 2001 has no oxygen sensor and it ECU runs in open loopalways!
 

On Dec 9, 12:03 pm, CMOS <manusha1...@gmail.com> wrote:
> Hi all,
> I recently bought an Elantra 2001 model car. When i did the emmission
> test, it failed with high CO and HC. CO percentage was in range 5-6.
> Its fuel consumption is also very high.
>
> The idle is very smooth, no knocking when accelerating and no other
> unusual behavior either.
>
> As the first thing, i replaced all spark plugs, got the distributor
> checked and wires checked. They are all fine. Then i did a fuel system
> clean and checked whether there are any problems with injectors and
> they were fine too.
>
> Today, i got its ECU scanned and it gave the code p0342. I replaced
> the camshaft position sensor, but it still gives the same code. In
> addition, the reading of oxygen sensor voltage is 0.0V always. When
> inspected, we could not find any oxygen sensor! And the engine runs
> always in open loop (even after it gets heated!). Now im fully
> confused! Please let me know whether there are engines where you don't
> have a oxygen sensor? And if there are engines like that, will they
> run in open loop always?
>
> thanks in advance!

You'll find the front oxygen sensor in the exhaust manifold-- it
screws into the transmission side of the manifold. The rear oxygen
sensor is in the front exhaust pipe. If you actually had no oxygen
sensor, you'd have trouble codes indicating an open heater circuit for
each sensor. I'll note, however, that since closed loop by definition
uses front oxygen sensor values to determine how much fuel to deliver,
lack of oxygen sensors would mean the vehicle would always operate in
open loop.

With the recurring P0342, you should check the camshaft timing. It's
possible that it's one tooth off. This would cause the emission
failure and the odd oxygen sensor readings.

Re: elantra 2001 has no oxygen sensor and it ECU runs in open loopalways!
 

On Dec 14, 10:18 am, hyundaitech <hyundaim...@gmail.com> wrote:
> On Dec 9, 12:03 pm, CMOS <manusha1...@gmail.com> wrote:
>
>
>
> > Hi all,
> > I recently bought an Elantra 2001 model car. When i did the emmission
> > test, it failed with high CO and HC. CO percentage was in range 5-6.
> > Its fuel consumption is also very high.
>
> > The idle is very smooth, no knocking when accelerating and no other
> > unusual behavior either.
>
> > As the first thing, i replaced all spark plugs, got the distributor
> > checked and wires checked. They are all fine. Then i did a fuel system
> > clean and checked whether there are any problems with injectors and
> > they were fine too.
>
> > Today, i got its ECU scanned and it gave the code p0342. I replaced
> > the camshaft position sensor, but it still gives the same code. In
> > addition, the reading of oxygen sensor voltage is 0.0V always. When
> > inspected, we could not find any oxygen sensor! And the engine runs
> > always in open loop (even after it gets heated!). Now im fully
> > confused! Please let me know whether there are engines where you don't
> > have a oxygen sensor? And if there are engines like that, will they
> > run in open loop always?
>
> > thanks in advance!
>
> You'll find the front oxygen sensor in the exhaust manifold-- it
> screws into the transmission side of the manifold. The rear oxygen
> sensor is in the front exhaust pipe. If you actually had no oxygen
> sensor, you'd have trouble codes indicating an open heater circuit for
> each sensor. I'll note, however, that since closed loop by definition
> uses front oxygen sensor values to determine how much fuel to deliver,
> lack of oxygen sensors would mean the vehicle would always operate in
> open loop.
>
> With the recurring P0342, you should check the camshaft timing. It's
> possible that it's one tooth off. This would cause the emission
> failure and the odd oxygen sensor readings.

Thanks for the valuable advice, i will check for timing.
BTW, i got the shop manual for the car and according to it, this car
was made for leaded petrol and has no oxygen sensors or catalytic
converters. As you have mentioned, this should run in open loop
always, i believe.
And one more help, Would a wear and tear of petrol injectors increase
the CO emission to 4%. The mileage of the car is 167000 KM.

thanks

Re: elantra 2001 has no oxygen sensor and it ECU runs in open loopalways!
 

On Dec 16, 2:24 am, CMOS <manusha1...@gmail.com> wrote:
> On Dec 14, 10:18 am, hyundaitech <hyundaim...@gmail.com> wrote:
>
>
>
> > On Dec 9, 12:03 pm, CMOS <manusha1...@gmail.com> wrote:
>
> > > Hi all,
> > > I recently bought an Elantra 2001 model car. When i did the emmission
> > > test, it failed with high CO and HC. CO percentage was in range 5-6.
> > > Its fuel consumption is also very high.
>
> > > The idle is very smooth, no knocking when accelerating and no other
> > > unusual behavior either.
>
> > > As the first thing, i replaced all spark plugs, got the distributor
> > > checked and wires checked. They are all fine. Then i did a fuel system
> > > clean and checked whether there are any problems with injectors and
> > > they were fine too.
>
> > > Today, i got its ECU scanned and it gave the code p0342. I replaced
> > > the camshaft position sensor, but it still gives the same code. In
> > > addition, the reading of oxygen sensor voltage is 0.0V always. When
> > > inspected, we could not find any oxygen sensor! And the engine runs
> > > always in open loop (even after it gets heated!). Now im fully
> > > confused! Please let me know whether there are engines where you don't
> > > have a oxygen sensor? And if there are engines like that, will they
> > > run in open loop always?
>
> > > thanks in advance!
>
> > You'll find the front oxygen sensor in the exhaust manifold-- it
> > screws into the transmission side of the manifold. The rear oxygen
> > sensor is in the front exhaust pipe. If you actually had no oxygen
> > sensor, you'd have trouble codes indicating an open heater circuit for
> > each sensor. I'll note, however, that since closed loop by definition
> > uses front oxygen sensor values to determine how much fuel to deliver,
> > lack of oxygen sensors would mean the vehicle would always operate in
> > open loop.
>
> > With the recurring P0342, you should check the camshaft timing. It's
> > possible that it's one tooth off. This would cause the emission
> > failure and the odd oxygen sensor readings.
>
> Thanks for the valuable advice, i will check for timing.
> BTW, i got the shop manual for the car and according to it, this car
> was made for leaded petrol and has no oxygen sensors or catalytic
> converters. As you have mentioned, this should run in open loop
> always, i believe.
> And one more help, Would a wear and tear of petrol injectors increase
> the CO emission to 4%. The mileage of the car is 167000 KM.
>
> thanks

Suppose I shouldn't have assumed. This car isn't in the U.S., is
it?

An injector issue would typically cause the car to run poorly, so that
isn't likely the issue. Stick with sorting out the reason for the cam
sensor code. Fixing that will likely fix the emissions.

Re: elantra 2001 has no oxygen sensor and it ECU runs in open loopalways!
 

On Dec 18, 12:56 pm, hyundaitech <hyundaim...@gmail.com> wrote:
> On Dec 16, 2:24 am, CMOS <manusha1...@gmail.com> wrote:
>
>
>
> > On Dec 14, 10:18 am, hyundaitech <hyundaim...@gmail.com> wrote:
>
> > > On Dec 9, 12:03 pm, CMOS <manusha1...@gmail.com> wrote:
>
> > > > Hi all,
> > > > I recently bought an Elantra 2001 model car. When i did the emmission
> > > > test, it failed with high CO and HC. CO percentage was in range 5-6..
> > > > Its fuel consumption is also very high.
>
> > > > The idle is very smooth, no knocking when accelerating and no other
> > > > unusual behavior either.
>
> > > > As the first thing, i replaced all spark plugs, got the distributor
> > > > checked and wires checked. They are all fine. Then i did a fuel system
> > > > clean and checked whether there are any problems with injectors and
> > > > they were fine too.
>
> > > > Today, i got its ECU scanned and it gave the code p0342. I replaced
> > > > the camshaft position sensor, but it still gives the same code. In
> > > > addition, the reading of oxygen sensor voltage is 0.0V always. When
> > > > inspected, we could not find any oxygen sensor! And the engine runs
> > > > always in open loop (even after it gets heated!). Now im fully
> > > > confused! Please let me know whether there are engines where you don't
> > > > have a oxygen sensor? And if there are engines like that, will they
> > > > run in open loop always?
>
> > > > thanks in advance!
>
> > > You'll find the front oxygen sensor in the exhaust manifold-- it
> > > screws into the transmission side of the manifold. The rear oxygen
> > > sensor is in the front exhaust pipe. If you actually had no oxygen
> > > sensor, you'd have trouble codes indicating an open heater circuit for
> > > each sensor. I'll note, however, that since closed loop by definition
> > > uses front oxygen sensor values to determine how much fuel to deliver,
> > > lack of oxygen sensors would mean the vehicle would always operate in
> > > open loop.
>
> > > With the recurring P0342, you should check the camshaft timing. It's
> > > possible that it's one tooth off. This would cause the emission
> > > failure and the odd oxygen sensor readings.
>
> > Thanks for the valuable advice, i will check for timing.
> > BTW, i got the shop manual for the car and according to it, this car
> > was made for leaded petrol and has no oxygen sensors or catalytic
> > converters. As you have mentioned, this should run in open loop
> > always, i believe.
> > And one more help, Would a wear and tear of petrol injectors increase
> > the CO emission to 4%. The mileage of the car is 167000 KM.
>
> > thanks
>
> Suppose I shouldn't have assumed. This car isn't in the U.S., is
> it?
>
> An injector issue would typically cause the car to run poorly, so that
> isn't likely the issue. Stick with sorting out the reason for the cam
> sensor code. Fixing that will likely fix the emissions.

thanks. the car was made for Sri Lanka.
Is there a place where i can but the correct manual for this car by
giving the VIN? i checked the local agent and they say they dont sell
it to customers. (so that they can have the service monopoly !)

Re: elantra 2001 has no oxygen sensor and it ECU runs in open loopalways!
 

On Dec 18, 11:35 pm, CMOS <manusha1...@gmail.com> wrote:
> thanks. the car was made for Sri Lanka.
> Is there a place where i can but the correct manual for this car by
> giving the VIN? i checked the local agent and they say they dont sell
> it to customers. (so that they can have the service monopoly !)

I'm not knowledgeable enough about non-US cars to know where that
would be. You can register for an account at www.hmaservice.com, but
it includes information only for U.S. models. At this point, I don't
know if your engine is the same as one of those available in the U.S.