OBD II codes P0410 and P1411

[jslebod1]

Hello,

These OBD II codes are "Secondary Air Injection Signal Implausible in cylinders 1-3 and 4-6". After browsing Porsche Pete's archives a couple days ago, I've seen 3-4 instances of this question posed in the past. I've got a '97 2.5L w/45,000 miles. I'd like to hear from somebody that has had to get the repair done to fix this issue, what did they fix, how much, etc...

I realize there will be different root causes for these codes, however I'd like to get a feel for if there is a a specific component in the secondary air system that generally causes these faults. I've heard from some that an air change over valve was replaced and fixed problem, and I've also heard of instances where the inlets into the cylinder heads get plugged due to carbon deposits. I've heard this is an expensive fix since the exhaust manifolds may need to be removed to pull these lines off and physically clean them out.

More background in my case, the air pump still appears to function fine, as it comes on for its normal cold start cycle every time I start car. It would just appear from the fault codes that the proper air flow isn't being read by the H20S sensors, can somebody comment. Thanks for any help!

[Loren]

Since the air pump does run that is a good sign. You could have a vacuum leak so check the hoses and connections first.

If that is not it you will need a PST2 or you will get the air pump to run to do the next tests.

Check the electric change-over valve: Disconnect the electrical connection to the electric change-over valve and connect a voltmeter to pin 1 (positive) and pin 2 (negative). When the pump runs you should see about 12 volts (battery voltage) there. Also, remove the hose and check for vacuum there.

If that appears ok then put everything back and proceed.

Check the air change over valve. Remove vacuum hose of air changeover valve. If vacuum is present at the air changeover valve, check air supply from the air pump to the change-over valve to the air supply line to the cylinder heads.

Check function of air changeover valve. Basically, if all the valves and circuits are working then you must have a plugged line.

1 - Secondary air injection pump

2 - Air change-over valve

3 - Electric change-over valve

4 - Non-return valve

5 - To the cylinder heads

6 - Vacuum reservoir

7 - To the intake air system

[jslebod1]

Loren,

Thanks for detailed trouble-shooting suggestions, I just need to find some time to give it a go! :cheers: How accessible is this system after removing the engine cover, will I need to come from under the carriage at all? Anybody have an engine compartment photo they could post showing most/all the secondary air system....thanks much!

[ecobb993]

I thought this was only an issue with 993s. Good to see we have company. Maybe Porsche will get on board with some help for us all.

:cheers: JC

[wgharper]

Sorry to dig up old topics, but I was wondering if anyone ever came to a conclusion on the cause of this malfunction. My CEL came on this weekend, and when I pulled the codes they were identical to those in the above post.

I also have a '97, with 48k miles (Just purchased last week :D ). I haven't done any troubleshooting, except that I had the codes cleared on Saturday and they came back this morning. I do hear the pump cycling on when cold (freaked me out at first...). Any insights would be appreciated.

Geoff

[Porsche_Joe]

I have had two problems in the secondary air system causing the codes you described. Both problems caused a slight change in the sound of the secondary air pump which I noticed before getting a CE light.

The first problem was a defective air injection valve (993-113-245-01). The cost for dealer replacement was $67.65 for the part and $279.30 for labor. Before the CE light came on I noticed the sound of the air pump was slightly lower; sounded like something was clogging one of the air lines creating resistance which caused the pump to operate at a slightly lower speed.

The second problem occurred the morning after the oil separator was replaced. I noticed the air pump seemed louder, like it was running at a higher speed. The oil separator is near the air pump so I figured an air hose was left disconnected causing less resistance for the air pump, hence the higher speed. It turned out there was a large crack in the tube that runs between the air change over valve and the electric changeover valve. The technician showed me the tube and it was very brittle so it was probably broken when he changed the oil separator. They did not charge me for the repair but it would have been relatively inexpensive.

[wgharper]

Thanks, Joe. I had seen a couple of posts on other boards about the air chang-over valve, so I'll start by taking that out and testing it once the weather clears up here. While I'm in there, I'll also check out the tube from the electric valve. Hopefully one or both of these are the cause, since everything else on the secondary injection system is buried in the engine compartment!

Either way, I'll post what I find.

Geoff

[wgharper]

Well, I replaced the air injection valve on Saturday (quite a knuckle buster), cleared the codes, and all appears to be well. The old valve could not hold a vacuum, so I am pretty confident that this was the source of the problem.

Thanks again to all who provided insight into this.

Geoff

[toothacts]

Well, I replaced the air injection valve on Saturday (quite a knuckle buster), cleared the codes, and all appears to be well.  The old valve could not hold a vacuum, so I am pretty confident that this was the source of the problem.

Thanks again to all who provided insight into this.

Geoff

<{POST_SNAPBACK}>

Hi Geoff; I appreciate all of you on this forum. I'm a new member and new owner of a 97 Boxster 2.5 with 44.000 miles. My CEL is on (learning a lot) replaced the MAF sensor before I bought an OBDII scanner because the MAF issue did not fix the problem. I discovered that I have one error code P1411 ( Secondary Air Injection System-Signal Implausable, Cylinders 4-6).

I was curious to your success, since you said that you replaced the air change over valve. I am about to tackle this job myself. Is this a DIY'er ? I know I need to check hoses for vacumm leaks first. Is the only way to get to this valve from above the car under the top, or can I get to the engine from the back seat as well?

Where did you find your air injection system parts ? Do I have to order them from the Porsche dealer. Any help or insight as to the P1411 error, and what area/part do you think I should check first ? Geoff, or anybody!

Thanks; Alan!

[Nader]

Alan,

I actually have the same problem on my '98. Replaced the MAF and both codes came back, 1-3 & 4-6 cylinders. I was also going to start checking all the hoses so please keep your progress posted so we can narrow down this issue.

Thanks,

Nader

[CJ_Boxster]

i got this same code today in the AM, I took the car to my fathers house and hooked up his odbII scanner and i got a P1411...I just cleared the code and it hasnt come back yet.

[toothacts]

i got this same code today in the AM, I took the car to my fathers house and hooked up his odbII scanner and i got a P1411...I just cleared the code and it hasnt come back yet.

Hi CJ;

I had this problem with the cel light a year ago, descibed in my previous post, replaced the Maf sensor hoping that it would fix the issue. It didn't fix the cel light problem, so I bought an obdII scanner and found a P1411 error code. I cleared the code and the cel light went out, only for a day or two and came back.

The P1411 refers to a problem within the secondary air injection system. Thanks to Loren's diagram, that shows the secondary air system, hoses etc. It is located beneath the plenum on the right side of the engine, looking down over the right rear fender. Without the proper tools and the system being hidden under the plenum, not sure if the parts would fix the problem, I took the car into a reputable German auto repair shop in the area. Here's the deal; I explained to the technician what I have learned from Renntech, and after diagnosing with his obdII scanner he found a P0410 and a P01411 my sensor only picked-up the P1411 error code. Turns out it was the a bad air change over valve #2 and # 3 electric change over valve (Loren's diagram). The hoses were replaced due to possible leaks. The air injection pump was fine.

It wound up costing me $ 600.00 however the aggravating cel light has been out for a year now.

[DUROC]

I posted the paragraph below yesterday on the 993 forum. It concerns the same OBD II codes others on this thread have experienced. I'm not technically qualified to say whether the fix I dreamed up could help with the underlying problem but I'd be greatful for the opinions of others, given the widespread nature of the problem. The dealer, incidentally, is recommending expensively cleaning cylinder head ports. Note that most of the posts about this problem seem to be from owners of 7-10 year old cars:

My 1997 C4S has had "check engine"/emissions test failures for several years. But I have just wire-brushed the corrosion off the screw-threaded brass gas cap and greased the threads with Vaseline to create a seal. The check engine light now seems to be staying off. I ran this experiment thinking -- without knowing anything about it -- that the design of the cap was intended to seal the tank and that if corrosion interfered with the seal, it might affect oxygen sensor readings or something like that. Question: Does this reasoning make any sense? Any advice about this would be very welcome. Thanks.

[CJ_Boxster]

I posted the paragraph below yesterday on the 993 forum. It concerns the same OBD II codes others on this thread have experienced. I'm not technically qualified to say whether the fix I dreamed up could help with the underlying problem but I'd be greatful for the opinions of others, given the widespread nature of the problem. The dealer, incidentally, is recommending expensively cleaning cylinder head ports. Note that most of the posts about this problem seem to be from owners of 7-10 year old cars:

My 1997 C4S has had "check engine"/emissions test failures for several years. But I have just wire-brushed the corrosion off the screw-threaded brass gas cap and greased the threads with Vaseline to create a seal. The check engine light now seems to be staying off. I ran this experiment thinking -- without knowing anything about it -- that the design of the cap was intended to seal the tank and that if corrosion interfered with the seal, it might affect oxygen sensor readings or something like that. Question: Does this reasoning make any sense? Any advice about this would be very welcome. Thanks.

It would if we knew weather not the vaccum canister in the air injection system sucks vaccum from the gas tank as do most cars. That would qualify as a leak. Ill give that a try before going to a mechanic.

[TimR]

Well, I replaced the air injection valve on Saturday (quite a knuckle buster), cleared the codes, and all appears to be well. The old valve could not hold a vacuum, so I am pretty confident that this was the source of the problem.

Thanks again to all who provided insight into this.

Geoff

Geoff, I know it's been a while since you did this project, but I am tackling this same repair, and I have a few questions. How did you get to the valves? Did you go in threw the firewall opening behind the seats which requires the alternator to be remove or did you go in from the top? If from the top, did you remove the air plentum to get to the valves?

Thanks.