would an exhaust leak cause lean or rich sensor reading?
12-28-2003, 11:46 AM
#11
Guest
Posts: n/a
Re: would an exhaust leak cause lean or rich sensor reading?
HMMMM
AFAIK the 02 sensors are heated so they come online sooner (closed loop
happens faster) and possibly before the engine warms up. I am not 100% sure
with the Jeeps though and have not timed mine....yet! :-)
I believe that if you do have an exhaust leak before the 02 sensor, you
system will run richer.
I gotta fix my XJ's exhaust manifold one of these days. lol
BTW it is probably best to watch how your system is performing with a
scanner/reader/tester for your system!
--
later,
dave
88 XJ 4.0 auto
82 Wag Ltd. 360 auto (to be retired!) anyone interested, whole or parts?
88 FSJ-GW 360 auto (GRAND 88)
Chicago
"bllsht" <nospam@invaliddot.net> wrote in message
news:v8ctuv0vent44g1cc4372jk2vo73k4khjs@4ax.com...
> The O2 sensor is ignored until the engine is warmed up, junior.
>
>
> In message <3FEDEA58.1060702@usefirstinitialandlastnameATerol s.com>,
"Simon
> Juncal" wrote:
>
> >Okay I know my old exhaust manifold is leaking, and is at it's worst
> >when cold so I'm wondering if a leaking manifold could fool the O2
> >sensor and cause the Cater stepper motor to go too rich, until the
> >engine gets a little warm (at which point the manifold has expanded from
> >the heat and sealed things up a little better) and then leans out.
> >
> >Would an exhaust leak before the O2 sensor cause rich or lean? In other
> >words would the sensor detect MORE O2 (lean) causing the computer to go
> >too rich?
> >
> >I'm about to get out and check the stepper metering pins to make sure
> >I've actually got a rich condition (pins all the way forward) and watch
> >it to see if it's backing down as the engine warms up.
>
AFAIK the 02 sensors are heated so they come online sooner (closed loop
happens faster) and possibly before the engine warms up. I am not 100% sure
with the Jeeps though and have not timed mine....yet! :-)
I believe that if you do have an exhaust leak before the 02 sensor, you
system will run richer.
I gotta fix my XJ's exhaust manifold one of these days. lol
BTW it is probably best to watch how your system is performing with a
scanner/reader/tester for your system!
--
later,
dave
88 XJ 4.0 auto
82 Wag Ltd. 360 auto (to be retired!) anyone interested, whole or parts?
88 FSJ-GW 360 auto (GRAND 88)
Chicago
"bllsht" <nospam@invaliddot.net> wrote in message
news:v8ctuv0vent44g1cc4372jk2vo73k4khjs@4ax.com...
> The O2 sensor is ignored until the engine is warmed up, junior.
>
>
> In message <3FEDEA58.1060702@usefirstinitialandlastnameATerol s.com>,
"Simon
> Juncal" wrote:
>
> >Okay I know my old exhaust manifold is leaking, and is at it's worst
> >when cold so I'm wondering if a leaking manifold could fool the O2
> >sensor and cause the Cater stepper motor to go too rich, until the
> >engine gets a little warm (at which point the manifold has expanded from
> >the heat and sealed things up a little better) and then leans out.
> >
> >Would an exhaust leak before the O2 sensor cause rich or lean? In other
> >words would the sensor detect MORE O2 (lean) causing the computer to go
> >too rich?
> >
> >I'm about to get out and check the stepper metering pins to make sure
> >I've actually got a rich condition (pins all the way forward) and watch
> >it to see if it's backing down as the engine warms up.
>
12-28-2003, 11:46 AM
#12
Guest
Posts: n/a
Re: would an exhaust leak cause lean or rich sensor reading?
HMMMM
AFAIK the 02 sensors are heated so they come online sooner (closed loop
happens faster) and possibly before the engine warms up. I am not 100% sure
with the Jeeps though and have not timed mine....yet! :-)
I believe that if you do have an exhaust leak before the 02 sensor, you
system will run richer.
I gotta fix my XJ's exhaust manifold one of these days. lol
BTW it is probably best to watch how your system is performing with a
scanner/reader/tester for your system!
--
later,
dave
88 XJ 4.0 auto
82 Wag Ltd. 360 auto (to be retired!) anyone interested, whole or parts?
88 FSJ-GW 360 auto (GRAND 88)
Chicago
"bllsht" <nospam@invaliddot.net> wrote in message
news:v8ctuv0vent44g1cc4372jk2vo73k4khjs@4ax.com...
> The O2 sensor is ignored until the engine is warmed up, junior.
>
>
> In message <3FEDEA58.1060702@usefirstinitialandlastnameATerol s.com>,
"Simon
> Juncal" wrote:
>
> >Okay I know my old exhaust manifold is leaking, and is at it's worst
> >when cold so I'm wondering if a leaking manifold could fool the O2
> >sensor and cause the Cater stepper motor to go too rich, until the
> >engine gets a little warm (at which point the manifold has expanded from
> >the heat and sealed things up a little better) and then leans out.
> >
> >Would an exhaust leak before the O2 sensor cause rich or lean? In other
> >words would the sensor detect MORE O2 (lean) causing the computer to go
> >too rich?
> >
> >I'm about to get out and check the stepper metering pins to make sure
> >I've actually got a rich condition (pins all the way forward) and watch
> >it to see if it's backing down as the engine warms up.
>
AFAIK the 02 sensors are heated so they come online sooner (closed loop
happens faster) and possibly before the engine warms up. I am not 100% sure
with the Jeeps though and have not timed mine....yet! :-)
I believe that if you do have an exhaust leak before the 02 sensor, you
system will run richer.
I gotta fix my XJ's exhaust manifold one of these days. lol
BTW it is probably best to watch how your system is performing with a
scanner/reader/tester for your system!
--
later,
dave
88 XJ 4.0 auto
82 Wag Ltd. 360 auto (to be retired!) anyone interested, whole or parts?
88 FSJ-GW 360 auto (GRAND 88)
Chicago
"bllsht" <nospam@invaliddot.net> wrote in message
news:v8ctuv0vent44g1cc4372jk2vo73k4khjs@4ax.com...
> The O2 sensor is ignored until the engine is warmed up, junior.
>
>
> In message <3FEDEA58.1060702@usefirstinitialandlastnameATerol s.com>,
"Simon
> Juncal" wrote:
>
> >Okay I know my old exhaust manifold is leaking, and is at it's worst
> >when cold so I'm wondering if a leaking manifold could fool the O2
> >sensor and cause the Cater stepper motor to go too rich, until the
> >engine gets a little warm (at which point the manifold has expanded from
> >the heat and sealed things up a little better) and then leans out.
> >
> >Would an exhaust leak before the O2 sensor cause rich or lean? In other
> >words would the sensor detect MORE O2 (lean) causing the computer to go
> >too rich?
> >
> >I'm about to get out and check the stepper metering pins to make sure
> >I've actually got a rich condition (pins all the way forward) and watch
> >it to see if it's backing down as the engine warms up.
>
12-28-2003, 11:46 AM
#13
Guest
Posts: n/a
Re: would an exhaust leak cause lean or rich sensor reading?
HMMMM
AFAIK the 02 sensors are heated so they come online sooner (closed loop
happens faster) and possibly before the engine warms up. I am not 100% sure
with the Jeeps though and have not timed mine....yet! :-)
I believe that if you do have an exhaust leak before the 02 sensor, you
system will run richer.
I gotta fix my XJ's exhaust manifold one of these days. lol
BTW it is probably best to watch how your system is performing with a
scanner/reader/tester for your system!
--
later,
dave
88 XJ 4.0 auto
82 Wag Ltd. 360 auto (to be retired!) anyone interested, whole or parts?
88 FSJ-GW 360 auto (GRAND 88)
Chicago
"bllsht" <nospam@invaliddot.net> wrote in message
news:v8ctuv0vent44g1cc4372jk2vo73k4khjs@4ax.com...
> The O2 sensor is ignored until the engine is warmed up, junior.
>
>
> In message <3FEDEA58.1060702@usefirstinitialandlastnameATerol s.com>,
"Simon
> Juncal" wrote:
>
> >Okay I know my old exhaust manifold is leaking, and is at it's worst
> >when cold so I'm wondering if a leaking manifold could fool the O2
> >sensor and cause the Cater stepper motor to go too rich, until the
> >engine gets a little warm (at which point the manifold has expanded from
> >the heat and sealed things up a little better) and then leans out.
> >
> >Would an exhaust leak before the O2 sensor cause rich or lean? In other
> >words would the sensor detect MORE O2 (lean) causing the computer to go
> >too rich?
> >
> >I'm about to get out and check the stepper metering pins to make sure
> >I've actually got a rich condition (pins all the way forward) and watch
> >it to see if it's backing down as the engine warms up.
>
AFAIK the 02 sensors are heated so they come online sooner (closed loop
happens faster) and possibly before the engine warms up. I am not 100% sure
with the Jeeps though and have not timed mine....yet! :-)
I believe that if you do have an exhaust leak before the 02 sensor, you
system will run richer.
I gotta fix my XJ's exhaust manifold one of these days. lol
BTW it is probably best to watch how your system is performing with a
scanner/reader/tester for your system!
--
later,
dave
88 XJ 4.0 auto
82 Wag Ltd. 360 auto (to be retired!) anyone interested, whole or parts?
88 FSJ-GW 360 auto (GRAND 88)
Chicago
"bllsht" <nospam@invaliddot.net> wrote in message
news:v8ctuv0vent44g1cc4372jk2vo73k4khjs@4ax.com...
> The O2 sensor is ignored until the engine is warmed up, junior.
>
>
> In message <3FEDEA58.1060702@usefirstinitialandlastnameATerol s.com>,
"Simon
> Juncal" wrote:
>
> >Okay I know my old exhaust manifold is leaking, and is at it's worst
> >when cold so I'm wondering if a leaking manifold could fool the O2
> >sensor and cause the Cater stepper motor to go too rich, until the
> >engine gets a little warm (at which point the manifold has expanded from
> >the heat and sealed things up a little better) and then leans out.
> >
> >Would an exhaust leak before the O2 sensor cause rich or lean? In other
> >words would the sensor detect MORE O2 (lean) causing the computer to go
> >too rich?
> >
> >I'm about to get out and check the stepper metering pins to make sure
> >I've actually got a rich condition (pins all the way forward) and watch
> >it to see if it's backing down as the engine warms up.
>
12-28-2003, 03:46 PM
#14
Guest
Posts: n/a
Re: would an exhaust leak cause lean or rich sensor reading?
L.W.(ßill) ------ III wrote:
> More than likely your Oxygen Sensor is history, kind of like up
> plugging it, it richens it, and has destroyed your catalytic convert by
> now.
The O2 sensor is new and the stepper motor initilizes indicating that
the O2 sensor (and computer and stepper) are working. The Cat is also new.
--
Simon
"I may be wrong, but I'm not uncertain." -- Robert A. Heinlein
> More than likely your Oxygen Sensor is history, kind of like up
> plugging it, it richens it, and has destroyed your catalytic convert by
> now.
The O2 sensor is new and the stepper motor initilizes indicating that
the O2 sensor (and computer and stepper) are working. The Cat is also new.
--
Simon
"I may be wrong, but I'm not uncertain." -- Robert A. Heinlein
12-28-2003, 03:46 PM
#15
Guest
Posts: n/a
Re: would an exhaust leak cause lean or rich sensor reading?
L.W.(ßill) ------ III wrote:
> More than likely your Oxygen Sensor is history, kind of like up
> plugging it, it richens it, and has destroyed your catalytic convert by
> now.
The O2 sensor is new and the stepper motor initilizes indicating that
the O2 sensor (and computer and stepper) are working. The Cat is also new.
--
Simon
"I may be wrong, but I'm not uncertain." -- Robert A. Heinlein
> More than likely your Oxygen Sensor is history, kind of like up
> plugging it, it richens it, and has destroyed your catalytic convert by
> now.
The O2 sensor is new and the stepper motor initilizes indicating that
the O2 sensor (and computer and stepper) are working. The Cat is also new.
--
Simon
"I may be wrong, but I'm not uncertain." -- Robert A. Heinlein
12-28-2003, 03:46 PM
#16
Guest
Posts: n/a
Re: would an exhaust leak cause lean or rich sensor reading?
L.W.(ßill) ------ III wrote:
> More than likely your Oxygen Sensor is history, kind of like up
> plugging it, it richens it, and has destroyed your catalytic convert by
> now.
The O2 sensor is new and the stepper motor initilizes indicating that
the O2 sensor (and computer and stepper) are working. The Cat is also new.
--
Simon
"I may be wrong, but I'm not uncertain." -- Robert A. Heinlein
> More than likely your Oxygen Sensor is history, kind of like up
> plugging it, it richens it, and has destroyed your catalytic convert by
> now.
The O2 sensor is new and the stepper motor initilizes indicating that
the O2 sensor (and computer and stepper) are working. The Cat is also new.
--
Simon
"I may be wrong, but I'm not uncertain." -- Robert A. Heinlein
12-28-2003, 04:09 PM
#17
Guest
Posts: n/a
Re: would an exhaust leak cause lean or rich sensor reading?
In message <qNDHb.15725$aw2.9006723@newssrv26.news.prodigy.co m>, "Dave" wrote:
>HMMMM
>AFAIK the 02 sensors are heated so they come online sooner (closed loop
>happens faster) and possibly before the engine warms up. I am not 100% sure
>with the Jeeps though and have not timed mine....yet! :-)
No heated O2 sensor on his Jeep, but even if it had one, when to attempt to go
into closed loop is determined by a coolant temp switch.
>
>I believe that if you do have an exhaust leak before the 02 sensor, you
>system will run richer.
>I gotta fix my XJ's exhaust manifold one of these days. lol
>BTW it is probably best to watch how your system is performing with a
>scanner/reader/tester for your system!
>HMMMM
>AFAIK the 02 sensors are heated so they come online sooner (closed loop
>happens faster) and possibly before the engine warms up. I am not 100% sure
>with the Jeeps though and have not timed mine....yet! :-)
No heated O2 sensor on his Jeep, but even if it had one, when to attempt to go
into closed loop is determined by a coolant temp switch.
>
>I believe that if you do have an exhaust leak before the 02 sensor, you
>system will run richer.
>I gotta fix my XJ's exhaust manifold one of these days. lol
>BTW it is probably best to watch how your system is performing with a
>scanner/reader/tester for your system!
12-28-2003, 04:09 PM
#18
Guest
Posts: n/a
Re: would an exhaust leak cause lean or rich sensor reading?
In message <qNDHb.15725$aw2.9006723@newssrv26.news.prodigy.co m>, "Dave" wrote:
>HMMMM
>AFAIK the 02 sensors are heated so they come online sooner (closed loop
>happens faster) and possibly before the engine warms up. I am not 100% sure
>with the Jeeps though and have not timed mine....yet! :-)
No heated O2 sensor on his Jeep, but even if it had one, when to attempt to go
into closed loop is determined by a coolant temp switch.
>
>I believe that if you do have an exhaust leak before the 02 sensor, you
>system will run richer.
>I gotta fix my XJ's exhaust manifold one of these days. lol
>BTW it is probably best to watch how your system is performing with a
>scanner/reader/tester for your system!
>HMMMM
>AFAIK the 02 sensors are heated so they come online sooner (closed loop
>happens faster) and possibly before the engine warms up. I am not 100% sure
>with the Jeeps though and have not timed mine....yet! :-)
No heated O2 sensor on his Jeep, but even if it had one, when to attempt to go
into closed loop is determined by a coolant temp switch.
>
>I believe that if you do have an exhaust leak before the 02 sensor, you
>system will run richer.
>I gotta fix my XJ's exhaust manifold one of these days. lol
>BTW it is probably best to watch how your system is performing with a
>scanner/reader/tester for your system!
12-28-2003, 04:09 PM
#19
Guest
Posts: n/a
Re: would an exhaust leak cause lean or rich sensor reading?
In message <qNDHb.15725$aw2.9006723@newssrv26.news.prodigy.co m>, "Dave" wrote:
>HMMMM
>AFAIK the 02 sensors are heated so they come online sooner (closed loop
>happens faster) and possibly before the engine warms up. I am not 100% sure
>with the Jeeps though and have not timed mine....yet! :-)
No heated O2 sensor on his Jeep, but even if it had one, when to attempt to go
into closed loop is determined by a coolant temp switch.
>
>I believe that if you do have an exhaust leak before the 02 sensor, you
>system will run richer.
>I gotta fix my XJ's exhaust manifold one of these days. lol
>BTW it is probably best to watch how your system is performing with a
>scanner/reader/tester for your system!
>HMMMM
>AFAIK the 02 sensors are heated so they come online sooner (closed loop
>happens faster) and possibly before the engine warms up. I am not 100% sure
>with the Jeeps though and have not timed mine....yet! :-)
No heated O2 sensor on his Jeep, but even if it had one, when to attempt to go
into closed loop is determined by a coolant temp switch.
>
>I believe that if you do have an exhaust leak before the 02 sensor, you
>system will run richer.
>I gotta fix my XJ's exhaust manifold one of these days. lol
>BTW it is probably best to watch how your system is performing with a
>scanner/reader/tester for your system!
12-28-2003, 04:55 PM
#20
Guest
Posts: n/a
Re: would an exhaust leak cause lean or rich sensor reading?
Nick N wrote:
> Simon, I just had this problem. I had a bad leak before the o2 sensor and
> my engine ran increadibly rich. It was mis-firing and failed emissions
> badly. I just had the leak fixed and my Jeep now runs great as a direct
> result.
> Nick
I've got a minor leak (or leaks), once it's warmed it runs like a clock
so I'm thinking the leaks are worse when it's really cold; causing or
contributing to it running really rich at startup.
--
Simon
"I may be wrong, but I'm not uncertain." -- Robert A. Heinlein
> Simon, I just had this problem. I had a bad leak before the o2 sensor and
> my engine ran increadibly rich. It was mis-firing and failed emissions
> badly. I just had the leak fixed and my Jeep now runs great as a direct
> result.
> Nick
I've got a minor leak (or leaks), once it's warmed it runs like a clock
so I'm thinking the leaks are worse when it's really cold; causing or
contributing to it running really rich at startup.
--
Simon
"I may be wrong, but I'm not uncertain." -- Robert A. Heinlein