J
JURB6006
Guest
Hi all;
This 94 Deville w/ 4.9 L is behaving more strangely than expected.
(bet you never heard it put that way before)
It rolled out of DeLorean's recently with a new rear O2 sensor. Symptom was
check engine would light after running awhile. Problem comes back, so he calls
me. Ran the codes and found a P013, "right O2 sensor not read" (<that is not a
misprint on my part), now this is a front wheel drive so if it has three O2
sensors the ones on the engine would be left and right, right ?, and the left
has been replaced. So we changed the "right" O2 sensor but the problem comes
back.
Now the codes read P013 "history" and P052 which is PCM reset. OK that seems
logical but why is the light on then ? There is no drivability problem, which
is usually normal for a bad O2 sensor, but it lights the light. Is it possible
it has the third sensor behind the cat and DeLorean changed the wrong one ?
Another thing I was hoping someone who knows this stuff could clear up is that
when I went back to the book, I noticed it says that this system doesn't have P
codes, it has E codes for the engine etc. Now this is a Chilton's, but it's all
we got on short notice. I know they make mistakes, could they have interpolated
the two charts ? I notice then that the P013 on that chart indicates a "heated
rear O2 sensor not ready" (<now ready, not read). If someone has the correct
info I would greatly appreciate it. (the front one is not heated)
Anyway, if they did indeed switch those charts, that means it is under warranty
by DeLorean's. They might balk at the fact that someone else changed something
else on it, but they really can't, they are still responsible for that part.
Now I've read notices in manuals not to even connect an ohmmeter or voltmeter
to an O2 sensor. Is this true ? I have not done it, and I'm also wondering how
you directly test these things. I'm not stupid and I know of course it would
entail running the engine up to temp, get it into closed loop if possible, then
connect the tester and through restricing air or causing a vacuum leak somehow
you have to be able to see something.
If the element is really so flimsy current wise, how do they get the signal to
the ECM or PCM in non-shielded cables ? How could some of them use engine
ground (single wire) without wreaking hovoc on the computer ? You would think
lead dress would be critical, but sometimes you see them right next to the
spark plug wires, what gives ? Taking a voltage reading might fry it ? I find
that a bit hard to believe.
I understand impedance, reactance etc., seems to me the ECM would have a heck
of alot of noise to deal with. If that's really the way it is, I'm suprised it
works at all.
Anything on this would be greatly appreciated, thanx in advance and thanx for
reading.
JURB
This 94 Deville w/ 4.9 L is behaving more strangely than expected.
(bet you never heard it put that way before)
It rolled out of DeLorean's recently with a new rear O2 sensor. Symptom was
check engine would light after running awhile. Problem comes back, so he calls
me. Ran the codes and found a P013, "right O2 sensor not read" (<that is not a
misprint on my part), now this is a front wheel drive so if it has three O2
sensors the ones on the engine would be left and right, right ?, and the left
has been replaced. So we changed the "right" O2 sensor but the problem comes
back.
Now the codes read P013 "history" and P052 which is PCM reset. OK that seems
logical but why is the light on then ? There is no drivability problem, which
is usually normal for a bad O2 sensor, but it lights the light. Is it possible
it has the third sensor behind the cat and DeLorean changed the wrong one ?
Another thing I was hoping someone who knows this stuff could clear up is that
when I went back to the book, I noticed it says that this system doesn't have P
codes, it has E codes for the engine etc. Now this is a Chilton's, but it's all
we got on short notice. I know they make mistakes, could they have interpolated
the two charts ? I notice then that the P013 on that chart indicates a "heated
rear O2 sensor not ready" (<now ready, not read). If someone has the correct
info I would greatly appreciate it. (the front one is not heated)
Anyway, if they did indeed switch those charts, that means it is under warranty
by DeLorean's. They might balk at the fact that someone else changed something
else on it, but they really can't, they are still responsible for that part.
Now I've read notices in manuals not to even connect an ohmmeter or voltmeter
to an O2 sensor. Is this true ? I have not done it, and I'm also wondering how
you directly test these things. I'm not stupid and I know of course it would
entail running the engine up to temp, get it into closed loop if possible, then
connect the tester and through restricing air or causing a vacuum leak somehow
you have to be able to see something.
If the element is really so flimsy current wise, how do they get the signal to
the ECM or PCM in non-shielded cables ? How could some of them use engine
ground (single wire) without wreaking hovoc on the computer ? You would think
lead dress would be critical, but sometimes you see them right next to the
spark plug wires, what gives ? Taking a voltage reading might fry it ? I find
that a bit hard to believe.
I understand impedance, reactance etc., seems to me the ECM would have a heck
of alot of noise to deal with. If that's really the way it is, I'm suprised it
works at all.
Anything on this would be greatly appreciated, thanx in advance and thanx for
reading.
JURB
