Bypass circuit for "Check Engine" Carbon build up..
04-03-2003, 09:59 PM
#18
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Great Job!!! WOW...this deserves an admin post...
I will include this in the FAQ for easy reference.
<img border="0" alt="[cheers]" title="" src="graemlins/beerchug.gif" />
I will include this in the FAQ for easy reference.
<img border="0" alt="[cheers]" title="" src="graemlins/beerchug.gif" />
07-21-2003, 07:25 PM
#19
Instructor
Better late than never so I'm bumping this, as I see some more questions related to the CE saga, my mechanic tells me he's starting to see it also on the 996's which I was not aware of.
Anyway , David sent out the ckt and I'm having trouble finding a decent/clean set of connectors, anyway the ckt and pics of the spots to plug it in in this write up here
Anyway , David sent out the ckt and I'm having trouble finding a decent/clean set of connectors, anyway the ckt and pics of the spots to plug it in in this write up here
07-22-2003, 09:05 AM
#20
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becker -
David has updated the circuit design, though the old one is probably effective too. I can email you the .jpg of the newer design if you wish.
Thanks for putting that up as a DIY!
Chip
David has updated the circuit design, though the old one is probably effective too. I can email you the .jpg of the newer design if you wish.
Thanks for putting that up as a DIY!
Chip
07-22-2003, 09:45 AM
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This is timely....my '96 with 41K miles (mostly highway miles) just gave me my first air-induction port CE light (4-6) last week. And I have a smog check that needs to be done by September...bad timing!
07-22-2003, 07:49 PM
#22
Instructor
Chip
I remember going back/forth w/David and mods to the original ckt, I want to try it out first and then see if the revised one makes a difference. I'll post my findings.
Cheers
I remember going back/forth w/David and mods to the original ckt, I want to try it out first and then see if the revised one makes a difference. I'll post my findings.
Cheers
07-22-2003, 11:15 PM
#23
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Hi 96P993
I have actually looked at this as a potential project/product for Rennlist since my car has logged a few misfires lately. I have had long email conversations with Dave, and he was kind enough to send me the circuit diagram, point out the potential places the solution could be installed. He also told me of potential liability issues which might prevent the commercialization of such as solution, and that I was free to take it to that level. Thanks for the help Dave!
The ideal solution for me would be something which is just plugs right in. Luckily the connectors to all four O2 sensors are in the engine bay. Unluckily those connectors are not easy to source in low volumes. I have been in touch with AMP and lots of their distributors and the connectors are sourced out of Germany ( of course), minimum order in over 1000pc lots....and lots of $$$ per unit.
As far as getting to the power side of the air pump I thought the best way would be to take apart a spare air pump relay, drill a hole in its case, and use that as the power source for the circuit.
This way the entire solution would be pluggable. I have done a board layout (my brother-in-lay has a small volume PC board facility) and I also received samples from AMP for the connectors so I could go ahead and try to put together a "pluggable" kit but it raises some questions:
1 - Most of the people I have talked to indicate that they would rather fix the problem then mask it so they would not be interested in such as kit.
2 - The kit would have to be sold as a off-road or test device only since disabling the air pump is against EPA regulations. Even then there might be liabilities back to the manufacturer.
3 - There is another liability risk since this kit is wired deep into the electrical circuits of the car. For instance, what happens if the ECU blows?
4 - For a pluggalbe professional kit (including the connectors, relay, circuit boards, wiring, labour for assembly and shipping and instructions all ready to plug in) the price point could end up as much as $200/kit. Is certainly cheaper than fixing the engine but it does not fix the problem, just masked it.
I will be putting something together for myself just because I have seen the problem but I have been sitting on the idea of a "Rennlist" kit because I was not sure of the acceptance of such a solution since, for example, there is quite an upfront investment in connectors required.
I guess we could cut into the wiring harness (on the O2 side so the car's main harness is not touched) and the would reduce the cost significantly but raise the risk higher that someone would not get it right. There are four wires to choose from, you have to get the right one! ;-)
What do you guys think?
I have actually looked at this as a potential project/product for Rennlist since my car has logged a few misfires lately. I have had long email conversations with Dave, and he was kind enough to send me the circuit diagram, point out the potential places the solution could be installed. He also told me of potential liability issues which might prevent the commercialization of such as solution, and that I was free to take it to that level. Thanks for the help Dave!
The ideal solution for me would be something which is just plugs right in. Luckily the connectors to all four O2 sensors are in the engine bay. Unluckily those connectors are not easy to source in low volumes. I have been in touch with AMP and lots of their distributors and the connectors are sourced out of Germany ( of course), minimum order in over 1000pc lots....and lots of $$$ per unit.
As far as getting to the power side of the air pump I thought the best way would be to take apart a spare air pump relay, drill a hole in its case, and use that as the power source for the circuit.
This way the entire solution would be pluggable. I have done a board layout (my brother-in-lay has a small volume PC board facility) and I also received samples from AMP for the connectors so I could go ahead and try to put together a "pluggable" kit but it raises some questions:
1 - Most of the people I have talked to indicate that they would rather fix the problem then mask it so they would not be interested in such as kit.
2 - The kit would have to be sold as a off-road or test device only since disabling the air pump is against EPA regulations. Even then there might be liabilities back to the manufacturer.
3 - There is another liability risk since this kit is wired deep into the electrical circuits of the car. For instance, what happens if the ECU blows?
4 - For a pluggalbe professional kit (including the connectors, relay, circuit boards, wiring, labour for assembly and shipping and instructions all ready to plug in) the price point could end up as much as $200/kit. Is certainly cheaper than fixing the engine but it does not fix the problem, just masked it.
I will be putting something together for myself just because I have seen the problem but I have been sitting on the idea of a "Rennlist" kit because I was not sure of the acceptance of such a solution since, for example, there is quite an upfront investment in connectors required.
I guess we could cut into the wiring harness (on the O2 side so the car's main harness is not touched) and the would reduce the cost significantly but raise the risk higher that someone would not get it right. There are four wires to choose from, you have to get the right one! ;-)
What do you guys think?
07-23-2003, 07:26 AM
#24
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I would be in on the kit. Haven't had the clogged air passages problem yet, but I'm assuming its only a matter of time, and I'm sure not going to spend the big bucks to actually clean those ports.
Chip
Chip
07-23-2003, 08:52 AM
#25
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I hate to sound like a whiner, but you would think Porsche Motorcars would recognize this problem is wide spread and come up with an acceptable and economical approach to fixing the problem. Their option is to have us so aggravated with the light that we'll go out and purchase a new 996 to fix the problem!
07-23-2003, 09:04 AM
#26
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Yup, you would think that Porsche would buck up but we all know, deep down, they they won't!
They are also inconsitent. I think it also depends on the local area rep, his budget, how much money you pour into the dealership, etc. For the DYI type of person its harder. I have an okay relationship with my local dealer but I don't see them very often, so the chances of them pushing the Porsche rep for me is unlikely. They did get Porsche to spend money on my Targa top though...
They are also inconsitent. I think it also depends on the local area rep, his budget, how much money you pour into the dealership, etc. For the DYI type of person its harder. I have an okay relationship with my local dealer but I don't see them very often, so the chances of them pushing the Porsche rep for me is unlikely. They did get Porsche to spend money on my Targa top though...
07-30-2003, 04:35 PM
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Mike it sounds like you are on the right track...I dont know if there is a permanent for the problem. Even with a rebuild the problem will come back eventually. I think the key to a kit would be ease of use..Could a person that has very little knowledge of cars install the kit?? I know the liability issue will always come up..Im not sure if a disclaimer would be enough to get past the problem..Are you looking for the O2 connectors that are inside the engine compartment? If so, what if the kit wasnt completely finished when shipped. If the connectors can be bought through the dealer then the buyer could get them and finish the kit up with provided instructions...I definitely think you are on the right track with this..now for the details...
07-30-2003, 07:48 PM
#29
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Mike J.
Thanks for working on this problem. I would think many, many people would be interested in a kit that masks the problem. I'm assuming that masking the problem will not cause any damage to the engine. Is that correct? That fact the carbon obstructs some passages does not in and of itself damage the engine, it just make the CE light go on, correct? If that's the case to me $200. is more that worth it avoid or delay an expensive engine disassembly.
On the issue of Porsche taking responsibility for the repairs I don't see that happening either. They would have to most likely be ordered by a court to pay for repairs before that would do so on a large scale.
If it's true that the problem with the passages being blocked by carbon is somehow a manufacturing or design flaw they should pay. However, I'm not qualified to make that assessment. If some is I wish they would speak up. If the problem is inevitable with nearly all 993's I sure would be willing to join any class action ( and contribute to attorney's fees and costs) to require Porsche to accept responsibility and pay for repairs.
Thanks for working on this problem. I would think many, many people would be interested in a kit that masks the problem. I'm assuming that masking the problem will not cause any damage to the engine. Is that correct? That fact the carbon obstructs some passages does not in and of itself damage the engine, it just make the CE light go on, correct? If that's the case to me $200. is more that worth it avoid or delay an expensive engine disassembly.
On the issue of Porsche taking responsibility for the repairs I don't see that happening either. They would have to most likely be ordered by a court to pay for repairs before that would do so on a large scale.
If it's true that the problem with the passages being blocked by carbon is somehow a manufacturing or design flaw they should pay. However, I'm not qualified to make that assessment. If some is I wish they would speak up. If the problem is inevitable with nearly all 993's I sure would be willing to join any class action ( and contribute to attorney's fees and costs) to require Porsche to accept responsibility and pay for repairs.
07-30-2003, 09:37 PM
#30
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You should look at Vehicle Warranties for 1995 and Newer Model Years then check out the list of similar recalls from http://www.epa.gov/otaq/recall.htm Other manufacturers have had to cover similar air recirculation problems. The important part of the emissions warranty is:
---------------------------
What Do I Do If the Manufacturer Will Not Honor What I Believe to Be a
Valid Emissions Warranty Claim?
If you believe the manufacturer has not honored a valid claim and
your vehicle has not exceeded the time and mileage limitations, you
should contact an authorized warranty representative and follow the
procedures outlined in your owner's manual or warranty booklet. If the
authorized dealer denies your warranty claim, contact the
manufacturer's regional or zone office for further assistance. If you
are still not satisfied, follow the appeals procedure outlined in your
manual or warranty booklet.
---------------------------------------
Of course, you are entitled to pursue any independent legal
actions you consider appropriate to obtain coverage under the
emissions warranties. In addition, the Environmental Protection
Agency (EPA) is authorized to investigate the failure of manufacturers
to comply with the terms of these warranties. If you have followed
the manufacturer's procedures (including those for appeals) for making
a warranty claim as set out in your owner's manual or warranty
booklet, have received a written denial and you are not satisfied with
the manufacturer's determination, you may submit a letter to EPA at
the following address. It should provide details of the situation
including the basis for the claim, a copy of the written denial,
copies of your letters to the manufacturers, and copies of any
receipts for emission control parts and repairs you have paid for:
U.S. Environmental Protection Agency
Vehicle Programs & Compliance Division (6405J)
Attn: Warranty Complaints
401 M Street, SW
Washington, DC 20460
Other sources of assistance may be your local or State consumer
protection agency or office of the Attorney General. You also should
be aware that low-cost or free legal assistance may be available
through a local legal aid office, the State bar association, or a law
school clinic staffed by law students.
----------------
If Ford, General Motors, Chrysler, Toyota, etc. manufactured a car that would fail emissions after 40k miles and require $6k to repair there would be hundreds of thousands of complaints and the car would be recalled.
---------------------------
What Do I Do If the Manufacturer Will Not Honor What I Believe to Be a
Valid Emissions Warranty Claim?
If you believe the manufacturer has not honored a valid claim and
your vehicle has not exceeded the time and mileage limitations, you
should contact an authorized warranty representative and follow the
procedures outlined in your owner's manual or warranty booklet. If the
authorized dealer denies your warranty claim, contact the
manufacturer's regional or zone office for further assistance. If you
are still not satisfied, follow the appeals procedure outlined in your
manual or warranty booklet.
---------------------------------------
Of course, you are entitled to pursue any independent legal
actions you consider appropriate to obtain coverage under the
emissions warranties. In addition, the Environmental Protection
Agency (EPA) is authorized to investigate the failure of manufacturers
to comply with the terms of these warranties. If you have followed
the manufacturer's procedures (including those for appeals) for making
a warranty claim as set out in your owner's manual or warranty
booklet, have received a written denial and you are not satisfied with
the manufacturer's determination, you may submit a letter to EPA at
the following address. It should provide details of the situation
including the basis for the claim, a copy of the written denial,
copies of your letters to the manufacturers, and copies of any
receipts for emission control parts and repairs you have paid for:
U.S. Environmental Protection Agency
Vehicle Programs & Compliance Division (6405J)
Attn: Warranty Complaints
401 M Street, SW
Washington, DC 20460
Other sources of assistance may be your local or State consumer
protection agency or office of the Attorney General. You also should
be aware that low-cost or free legal assistance may be available
through a local legal aid office, the State bar association, or a law
school clinic staffed by law students.
----------------
If Ford, General Motors, Chrysler, Toyota, etc. manufactured a car that would fail emissions after 40k miles and require $6k to repair there would be hundreds of thousands of complaints and the car would be recalled.