Unexpected SES light... questions
Thread Starter
Joined: Dec 2004
Posts: 1,294
Likes: 0
From: Dallas (Richardson), TX, USA
Unexpected SES light... questions I installed headers on my car a little over a month ago. Both my cats have blown since then (long story). The SES light has been on pretty much non-stop ever since. There were two reasons for this (that I was aware of). First, I didn't yet have my O2 sims, so I was running with no rear O2s. Second, I had the fuse on the AIR pump (which is not connected since I have race headers) removed.
So, I got sims, installed them, reset the computer, and boom... light came right back on. Then, last night, I put the fuse back in on the AIR pump (which is just blowing air into the engine compartment right now, not the exhaust), and boom... light came on again this morning. I have a few questions now, since my inspection expires this month:
1) Can the computer tell that the AIR pump is not connected to the headers? If so, how?
2) Can I remove the AIR pump from the computer and pass inspection?
3) Where can I find out what code is being thrown for cheap?
4) Do you guys have any other useful info to offer?
TIA, guys.
So, I got sims, installed them, reset the computer, and boom... light came right back on. Then, last night, I put the fuse back in on the AIR pump (which is just blowing air into the engine compartment right now, not the exhaust), and boom... light came on again this morning. I have a few questions now, since my inspection expires this month:
1) Can the computer tell that the AIR pump is not connected to the headers? If so, how?
2) Can I remove the AIR pump from the computer and pass inspection?
3) Where can I find out what code is being thrown for cheap?
4) Do you guys have any other useful info to offer?
TIA, guys.
Find a good tuner in your area and get the AIR and rear O2 stuff deleted and get a performance tune while you're at it. If you guys have tailpipe testing you'll have to have cats on, at least at testing time.
Originally Posted by Gauge
I installed headers on my car a little over a month ago. Both my cats have blown since then (long story). The SES light has been on pretty much non-stop ever since. There were two reasons for this (that I was aware of). First, I didn't yet have my O2 sims, so I was running with no rear O2s. Second, I had the fuse on the AIR pump (which is not connected since I have race headers) removed.
So, I got sims, installed them, reset the computer, and boom... light came right back on. Then, last night, I put the fuse back in on the AIR pump (which is just blowing air into the engine compartment right now, not the exhaust), and boom... light came on again this morning. I have a few questions now, since my inspection expires this month:
1) Can the computer tell that the AIR pump is not connected to the headers? If so, how?
2) Can I remove the AIR pump from the computer and pass inspection?
3) Where can I find out what code is being thrown for cheap?
4) Do you guys have any other useful info to offer?
TIA, guys.
So, I got sims, installed them, reset the computer, and boom... light came right back on. Then, last night, I put the fuse back in on the AIR pump (which is just blowing air into the engine compartment right now, not the exhaust), and boom... light came on again this morning. I have a few questions now, since my inspection expires this month:
1) Can the computer tell that the AIR pump is not connected to the headers? If so, how?
2) Can I remove the AIR pump from the computer and pass inspection?
3) Where can I find out what code is being thrown for cheap?
4) Do you guys have any other useful info to offer?
TIA, guys.
2. Depends on who is inspecting your car. If they pop the hood and know it is supposed to be there and it is not, they are probably going to fail it.
3. Go to Autozone and have the code pulled for FREE. It might be something different.
4. I agree with above. Find a good tuner and have a tune done, and the AIR deleted with the rear 02's.
Thread Starter
Joined: Dec 2004
Posts: 1,294
Likes: 0
From: Dallas (Richardson), TX, USA
First of all, in Texas we do OBDII inspections foro '96 and newer, so I have that going for me. I'm just wondering what could be throwing this code. I have a couple other questions...
1) shouldaboughttheZ says that the computer cannot determine if the AIR pump is connected to the exhaust manifolds... everyone agree with this? Is there any way for the computer to determine that the AIR pump is removed entirely? (i.e. front O2's can detect no additional air flow when car is cold, computer can tell that no electrical current is flowing to the pump, etc)
2) Why should I have to remove the rear O2's if I have sims? Shouldn't they be sufficient?
1) shouldaboughttheZ says that the computer cannot determine if the AIR pump is connected to the exhaust manifolds... everyone agree with this? Is there any way for the computer to determine that the AIR pump is removed entirely? (i.e. front O2's can detect no additional air flow when car is cold, computer can tell that no electrical current is flowing to the pump, etc)
2) Why should I have to remove the rear O2's if I have sims? Shouldn't they be sufficient?
What happens is the PCM runs a diagnostic every so often and it triggers the AIR pump to send air into the exhaust. If the O2's do not "see" the extra air from the AIR pump test then the test fails and the PCM sets a code.
Originally Posted by Gauge
First of all, in Texas we do OBDII inspections foro '96 and newer, so I have that going for me. I'm just wondering what could be throwing this code. I have a couple other questions...
1) shouldaboughttheZ says that the computer cannot determine if the AIR pump is connected to the exhaust manifolds... everyone agree with this? Is there any way for the computer to determine that the AIR pump is removed entirely? (i.e. front O2's can detect no additional air flow when car is cold, computer can tell that no electrical current is flowing to the pump, etc)
2) Why should I have to remove the rear O2's if I have sims? Shouldn't they be sufficient?
1) shouldaboughttheZ says that the computer cannot determine if the AIR pump is connected to the exhaust manifolds... everyone agree with this? Is there any way for the computer to determine that the AIR pump is removed entirely? (i.e. front O2's can detect no additional air flow when car is cold, computer can tell that no electrical current is flowing to the pump, etc)
2) Why should I have to remove the rear O2's if I have sims? Shouldn't they be sufficient?
2. The tuner can remove the rear 02's on the car, which makes the sims useless, sell them and put the money towards something else. This is what I did. And if you are running an M6, the tuner can take the skip shift out also.
Originally Posted by Dustin Butts
What happens is the PCM runs a diagnostic every so often and it triggers the AIR pump to send air into the exhaust. If the O2's do not "see" the extra air from the AIR pump test then the test fails and the PCM sets a code.
Tony, Id be willing to bet that youre simply got the good 'ol slow switching / heater codes on the front oxygen sensors. See, since headers move the sensors further down stream, the exhaust is cool, and this tends to kill oxygen sensors in relatively short order. Some last longer than others, but its luck of the draw. Like they said, go to autozone and get them to pull your codes. Everything else youve got seems to be in order.
-Tony
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Do you have a factory service manual? If so... check it out. From my 98 service manual:
"P1415 Secondary AIR System Bank 1:
An AIR pump is used on this vehicle to lower tailpipe emissions on start-up. The PCM supplies a ground to the AIR pump relay, which energizes the AIR pump.
The PCM monitors the HO2S voltages to diagnose the AIR system.
During the AIR test the PCM activates the AIR pump during closed loop operation. When the AIR is activated, the PCM monitors the HO2S voltages and short term fuel trim values for both banks of the engine. If the AIR system is operating properly, the HO2S voltages should go low and the short term fuel trim should go high.
If the PCM determines that the HO2S voltages for both banks did not respond as expected during the tests, DTC P0410 sets. If only one sensor responded, the PCM sets either a DTC P1415 or P1416 to indicate which bank the AIR system is inoperative."
I'm sure this system works the same for all models that have it. So you can see that PCM programming is a must to remove this code for good, if you have a disabled or deleted AIR system.
"P1415 Secondary AIR System Bank 1:
An AIR pump is used on this vehicle to lower tailpipe emissions on start-up. The PCM supplies a ground to the AIR pump relay, which energizes the AIR pump.
The PCM monitors the HO2S voltages to diagnose the AIR system.
During the AIR test the PCM activates the AIR pump during closed loop operation. When the AIR is activated, the PCM monitors the HO2S voltages and short term fuel trim values for both banks of the engine. If the AIR system is operating properly, the HO2S voltages should go low and the short term fuel trim should go high.
If the PCM determines that the HO2S voltages for both banks did not respond as expected during the tests, DTC P0410 sets. If only one sensor responded, the PCM sets either a DTC P1415 or P1416 to indicate which bank the AIR system is inoperative."
I'm sure this system works the same for all models that have it. So you can see that PCM programming is a must to remove this code for good, if you have a disabled or deleted AIR system.
Last edited by Dustin Butts; Jun 4, 2005 at 06:26 AM.
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