Misfire codes

[DaveE]

My car is a '97 Boxster, 2.5l 5-spd, with 106,000 miles. When I started it up this morning it began idling very rough and the CEL came on, flashing at first then steady. Since the light stopped flashing I drove the car a bit and it ran fine, except for the rough idle. I hooked up the Durametric and found the following codes, p1319, p1318, p1316, p1317, p0157, p0300, p0306, p0304, and p0305. These all are related to #4-6 cylinders and from searches of the misfire it usually points to checking the ignition coils but it seems pretty odd to me that all 3 coils on one side would fail at the same time. What else in common could cause this? Cam timing maybe? Any ideas?

Also, is there a detailed OBD manual available that goes into a little in-depth troubleshooting of the fault codes? I live in the middle of Western PA. The nearest dealer to the east of me is about 125 miles, in Harrisburg, and to the west about 100 miles, in Pittsburgh. There is no one close to me that I would trust my Porsche to.

Edited November 28, 2007 by DaveE

[pk2]

My car is a '97 Boxster, 2.5l 5-spd, with 106,000 miles. When I started it up this morning it began idling very rough and the CEL came on,... There is no one close to me that I would trust my Porsche to.

I can think of one thing that might screw up a whole bank of cylinders. That might be a vacume leak in the induction system for that side. Although that would probably show up to some degree in the other bank…hmm.

After a good look around, I’d get some starter fluid and spray it around the joints of the intake manifold, if you hear your engine rev a bit…that’s a problem.

Good luck.

PK

[1schoir]

My car is a '97 Boxster, 2.5l 5-spd, with 106,000 miles. When I started it up this morning it began idling very rough and the CEL came on, flashing at first then steady. Since the light stopped flashing I drove the car a bit and it ran fine, except for the rough idle. I hooked up the Durametric and found the following codes, p1319, p1318, p1316, p1317, p0157, p0300, p0306, p0304, and p0305. These all are related to #4-6 cylinders and from searches of the misfire it usually points to checking the ignition coils but it seems pretty odd to me that all 3 coils on one side would fail at the same time. What else in common could cause this? Cam timing maybe? Any ideas?

Also, is there a detailed OBD manual available that goes into a little in-depth troubleshooting of the fault codes? I live in the middle of Western PA. The nearest dealer to the east of me is about 125 miles, in Harrisburg, and to the west about 100 miles, in Pittsburgh. There is no one close to me that I would trust my Porsche to.

Dave:

I have a MY97 Boxster w/ MY98 2.5L engine, 5 speed, with only 16,000 miles and I had almost the exact same codes and symptoms that you describe about two months ago.

The ONLY difference was that mine were a mirror image of yours, with the fault codes indicating cylinders #1-3.

My CEL also flashed briefly, and my codes were p1319, p1313, p1314, p1315, p300, p301,p302, and p303.

I agree with your comment about the unlikelihood of all 3 ignition coils going bad at the same time.

I never found out exactly what caused them, reset the CEL, and I have not gotten those particular codes again. However, about two weeks ago, I started to get P1128 (Oxygen sensing range 2, cylinders 1-3), which I have reset twice and which has returned two more times as P1128.

About 6 months ago I replaced the O2 sensor AHEAD of the cat on cylinders 1-3 side, and will now be replacing the O2 sensor AFTER the cat to resolve the P1128 code. At least that is my current thinking.

I would be curious to know if you now get a code similar to P1128, only for the cylinders 4-6.

Regards, Maurice.

[DaveE]

Dave:

I have a MY97 Boxster w/ MY98 2.5L engine, 5 speed, with only 16,000 miles and I had almost the exact same codes and symptoms that you describe about two months ago.

The ONLY difference was that mine were a mirror image of yours, with the fault codes indicating cylinders #1-3.

My CEL also flashed briefly, and my codes were p1319, p1313, p1314, p1315, p300, p301,p302, and p303.

I agree with your comment about the unlikelihood of all 3 ignition coils going bad at the same time.

I never found out exactly what caused them, reset the CEL, and I have not gotten those particular codes again. However, about two weeks ago, I started to get P1128 (Oxygen sensing range 2, cylinders 1-3), which I have reset twice and which has returned two more times as P1128.

About 6 months ago I replaced the O2 sensor AHEAD of the cat on cylinders 1-3 side, and will now be replacing the O2 sensor AFTER the cat to resolve the P1128 code. At least that is my current thinking.

I would be curious to know if you now get a code similar to P1128, only for the cylinders 4-6.

Regards, Maurice.

Maurice, I also get a P0157 code, which is for the O2 sensor behind the cat, same side, 4 thru 6. I reset all the codes and will see if they come back in the morning. After further investigating my misfire I'm thinking that maybe the VarioCam solenoid might be the culprit. I'm not sure if that is something I can change or not. These codes only appear when I come to a stop and the car idles for a little. I clear them and take it out and drive it and it's OK. If I keep the revs up just even a little I get no CEL.

Edited November 28, 2007 by DaveE

[1schoir]

Dave:

I have a MY97 Boxster w/ MY98 2.5L engine, 5 speed, with only 16,000 miles and I had almost the exact same codes and symptoms that you describe about two months ago.

The ONLY difference was that mine were a mirror image of yours, with the fault codes indicating cylinders #1-3.

My CEL also flashed briefly, and my codes were p1319, p1313, p1314, p1315, p300, p301,p302, and p303.

I agree with your comment about the unlikelihood of all 3 ignition coils going bad at the same time.

I never found out exactly what caused them, reset the CEL, and I have not gotten those particular codes again. However, about two weeks ago, I started to get P1128 (Oxygen sensing range 2, cylinders 1-3), which I have reset twice and which has returned two more times as P1128.

About 6 months ago I replaced the O2 sensor AHEAD of the cat on cylinders 1-3 side, and will now be replacing the O2 sensor AFTER the cat to resolve the P1128 code. At least that is my current thinking.

I would be curious to know if you now get a code similar to P1128, only for the cylinders 4-6.

Regards, Maurice.

Maurice, I also get a P0157 code, which is for the O2 sensor behind the cat, same side, 4 thru 6. I reset all the codes and will see if they come back in the morning. After further investigating my misfire I'm thinking that maybe the VarioCam solenoid might be the culprit. I'm not sure if that is something I can change or not. These codes only appear when I come to a stop and the car idles for a little. I clear them and take it out and drive it and it's OK. If I keep the revs up just even a little I get no CEL.

Dave:

Thanks for the info. One more thing that I forgot to mention.

I remember (about 4 months ago), when I got my first set of CEL codes, my Durametric gave me a code number for the O2 sensor AFTER the cat on cylinders 1-3, but it actually should have given that number for the O2 sensor BEFORE the cat. I contacted Durametric and they confirmed that it was a glitch. They were (and always are) very responsive.

I forgot what the actual (wrong) code number was, but I posted it here and Loren gave me the correct information. If I can find that post or code number, I'll repost it here on the off chance that you might run into the same problem (and then replace the wrong O2 sensor).

By the way, don't spend the extra money for a "Porsche" O2 sensor, get a Bosch one for a lot less. Bosch is the actual manufacturer for Porsche's O2 sensors, then Porsche puts them in a Porsche box after stamping their numbers on them and then they double the price of the O2 sensor. Also, I got the ones that come with the correct connector because I understand that you cannot solder the leads on an O2 sensor without affecting their operation. Don't know how accurate that is, and some people crimp on the connector wires, but I don't think it's worth the extra hassle. Too many CEL's as it is.

I got mine from AutohauszAZ.com for about $136.58, no shipping.

Keep us posted.

Regards, Maurice.

Edited December 2, 2007 by 1schoir

[vizcarra44]

Dave:

I have a MY97 Boxster w/ MY98 2.5L engine, 5 speed, with only 16,000 miles and I had almost the exact same codes and symptoms that you describe about two months ago.

The ONLY difference was that mine were a mirror image of yours, with the fault codes indicating cylinders #1-3.

My CEL also flashed briefly, and my codes were p1319, p1313, p1314, p1315, p300, p301,p302, and p303.

I agree with your comment about the unlikelihood of all 3 ignition coils going bad at the same time.

I never found out exactly what caused them, reset the CEL, and I have not gotten those particular codes again. However, about two weeks ago, I started to get P1128 (Oxygen sensing range 2, cylinders 1-3), which I have reset twice and which has returned two more times as P1128.

About 6 months ago I replaced the O2 sensor AHEAD of the cat on cylinders 1-3 side, and will now be replacing the O2 sensor AFTER the cat to resolve the P1128 code. At least that is my current thinking.

I would be curious to know if you now get a code similar to P1128, only for the cylinders 4-6.

Regards, Maurice.

Maurice, I also get a P0157 code, which is for the O2 sensor behind the cat, same side, 4 thru 6. I reset all the codes and will see if they come back in the morning. After further investigating my misfire I'm thinking that maybe the VarioCam solenoid might be the culprit. I'm not sure if that is something I can change or not. These codes only appear when I come to a stop and the car idles for a little. I clear them and take it out and drive it and it's OK. If I keep the revs up just even a little I get no CEL.

Dave:

Thanks for the info. One more thing that I forgot to mention.

I remember (about 4 months ago), when I got my first set of CEL codes, my Durametric gave me a code number for the O2 sensor AFTER the cat on cylinders 1-3, but it actually should have given that number for the O2 sensor BEFORE the cat. I contacted Durametric and they confirmed that it was a glitch. They were (and always are) very responsive.

I forgot what the actual (wrong) code number was, but I posted it here and Loren gave me the correct information. If I can find that post or code number, I'll repost it here on the off chance that you might run into the same problem (and then replace the wrong O2 sensor).

By the way, don't spend the extra money for a "Porsche" O2 sensor, get a Bosch one for a lot less. Bosch is the actual manufacturer for Porsche's O2 sensors, then Porsche puts them in a Porsche box after stamping their numbers on them and then they double the price of the O2 sensor. Also, I got the ones that come with the correct connector because I understand that you cannot solder the leads on an O2 sensor without affecting their operation. Don't know how accurate that is, and some people crimp on the connector wires, but I don't think it's worth the extra hassle. Too many CEL's as it is.

I got mine from AutohauszAZ.com for about $136.58, no shipping.

Keep us posted.

Regards, Maurice.

Regards, Maurice.

If the downstream o2 sensor is bad it can cause a super rich misfire condition. Check the volts and if it is below 0volts then its bad or wiring. If it switches just as fast as the upstream then the cat converter is gutted by a misfire condition that was caused by the downstream o2 sensor most likely. If the sensor is operating fine and voltage is staying steady above650mv then its ok. Now to determine if you have an internal Misfire such as mechanical problems or external such as injectors or coils, I would look at the Oxygen sensor voltage -upstream voltage. Preferably with a graphing scanner to get a good visual on the applitude and frequency it generates. If the voltage is hanging higher above 650mv then you have a mechanical problem, and if you have an external misfire then you will see low o2 sensor voltages as well as fuel trim in the positive range. If you had a scanner that could deactivate the injectors and coils individually you would be able to nawrrow down this misfire. By the way if you get a flashing Mil light turn your car off cause your going to fry your cat converter.

Things can get expensive when you dont have the right Diagnostic scanner.

Good Luck

Vizcarra44

Edited November 29, 2007 by vizcarra44

[DaveE]

Maurice and Viscarra44, thanks for the info. I just bought this car about a month ago. The PO had just replaced all 4 O2 sensors but he said he got them from Auto Zone or Advance so now I'm thinking that this could be my problem. I have gotten faults for O2 sensors twice before and just cleared the codes. I plan to spend the day under the car investigating this. I hope it is only O2 sensors but I think I have a scheme for checking the VarioCam solenoid also, if need be. Unfortunately the only diagnostic tool I have is the Durametric.

Thanks for the help.

Edited November 29, 2007 by DaveE

[1schoir]

Maurice and Viscarra44, thanks for the info. I just bought this car about a month ago. The PO had just replaced all 4 O2 sensors but he said he got them from Auto Zone or Advance so now I'm thinking that this could be my problem. I have gotten faults for O2 sensors twice before and just cleared the codes. I plan to spend the day under the car investigating this. I hope it is only O2 sensors but I think I have a scheme for checking the VarioCam solenoid also, if need be. Unfortunately the only diagnostic tool I have is the Durametric.

Thanks for the help.

Dave:

I found the thread which deals with the possible Durametric code error, if you are interested in reading it. Here is the link:

http://www.renntech.org/forums/index.php?s...amp;#entry75252

Regards, Maurice.

[DaveE]

Thanks for that info, Maurice. That will help me. I'm still working on this issue and will post what I find to be the problem. I'm suspecting the rear O2 sensor or wiring at this point.

Edited December 3, 2007 by DaveE

[DaveE]

Thanks for that info, Maurice. That will help me. I'm still working on this issue and will post what I find to be the problem. I'm suspecting the rear O2 sensor or wiring at this point.

To follow up, I replaced both O2 sensors for cyl 4-6 yesterday afternoon. They were the low price crimp on versions that the PO had purchased approximately 10K miles ago. I mostly suspected that the rear was bad, judging from the real-time data on the Durametric program and info from vizcarra44's post (Thanks!). I purchased sensors from Autohaus AZ with the plugs, the "OEM replacements". When I first drove the car immediately after, I once again got the 6 misfire codes after sitting at a traffic light for only a few seconds, but no O2 sensor codes this time. After resetting, I was able to let the car idle and it idled properly for several minutes. I drove it this morning, stopping and idling several times, during my 74 mile drive, and still no CEL. If this continues I will replace the O2 sensors on the passenger side as well, since the readings side to side are a bit different and they are also the cheap versions.

[1schoir]

Thanks for that info, Maurice. That will help me. I'm still working on this issue and will post what I find to be the problem. I'm suspecting the rear O2 sensor or wiring at this point.

To follow up, I replaced both O2 sensors for cyl 4-6 yesterday afternoon. They were the low price crimp on versions that the PO had purchased approximately 10K miles ago. I mostly suspected that the rear was bad, judging from the real-time data on the Durametric program and info from vizcarra44's post (Thanks!). I purchased sensors from Autohaus AZ with the plugs, the "OEM replacements". When I first drove the car immediately after, I once again got the 6 misfire codes after sitting at a traffic light for only a few seconds, but no O2 sensor codes this time. After resetting, I was able to let the car idle and it idled properly for several minutes. I drove it this morning, stopping and idling several times, during my 74 mile drive, and still no CEL. If this continues I will replace the O2 sensors on the passenger side as well, since the readings side to side are a bit different and they are also the cheap versions.

Thanks for posting the update, Dave!

Regards, Maurice.

[moosey]

Would P0304,P0446,P1316 cause check engine light to flash???

[JFP in PA]

Being emissions related codes, they could to preserve the three way cats.

[moosey]

2 hours ago, JFP in PA said:

Being emissions related codes, they could to preserve the three way cats.

Hi JFP thanks . I got the three codes mentioned above. The car has 198k . I drained the oil and there was no oil mix. Could AOS be partial problem? I’m going to check banks two cylinder 4 coil plug . Also read on some post the p0446 has something to do with bad Camshaft sensor bank 2? So if it’s emission related engine should be okay?

[JFP in PA]

P0446 is for an EVAP shutoff valve malfunction, usually because the purge like is blocked.  It has nothing to do with the cams.