Sudden P0300/P0301/P0302/P0303 codes

Hi all...first off I'm a newbie having just bought a 2000 Carrera Cab last weekend...and drove it back from Alabama to NY with no problems. But today started the car for a store run and as I got about 1/4 mile away the CEL started flashing. Turned right around and parked at home and pulled the codes. Codes were all misfire and appears to affect the entire drivers bank...so other pending or stored codes. Car has driven flawlessly for about 1500 miles in past week with no other symptoms of anything amiss. I know that often indicates coils...but seems odd all three on one side would happen at once. MAF I suspect would affect both sides (although maybe not). AOS is very recent...guidance on how to whittle down causes and things to test. It's already going to a local shop for check over on Tuesday as well...as I think I may have pinion bearing starting to make noise...frustrated for sure that the first week has been a bit rough other than the 1200 mile drive back which was awesome. Thanks in advance...look forward to people's thoughts...

Does it run rough? tried resetting the codes and see if they come back?

Bank 1 (driver's side) has given me misfires. My issue was cracked coils aggravated by a coolant leak. If you don't have records or an idea of when the coil packs were last replaced, it's a relatively inexpensive option to start troubleshooting. Coils & plugs, then retest. Crank sensor is a cheap replacement that can cause misfires, though having only one bank cause issues seems like something local triggered it while leaving bank 2 ok. The coolant expansion tank is driver's side along with some piping, so that's why I brought that up. I guess mayyyybe fuel pressure sensor or something specific to the bank one fuel rail could cause it to stop detonating, but I'm not familiar with that system yet.

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Yup...it does indeed hesitate, and that is when it starts the flashing CEL. I did reset codes and it does indeed come back. Last night was first time having the car where it got down to around 50 degrees and lots of dew this morning. Codes are same...no other codes beyond the 4 misfires. Have not brought up to full operating temp though today to see if goes away. Did not want to damage cats...

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I do have record of coolant expansion tank being recently replaced and no signs of coolant leak. I have good records on the car but did not see anything for coils since at least 2009...plugs and tubes show to be done in 2011. I've ordered coils and plugs from Pelican and will start there for sure. Likely will pull MAF tomorrow as well and clean. Was also wondering about fuel delivery...but is at low RPMs and came on REALLY suddenly...

Sounds like you're on the right track. Bank 2 is where the ugly cylinder stuff happens with the m96 so I'd try not to sweat it too much until you get new coil packs & plugs in. Preexisting or not, these things will happen. Let us know how it goes.

So this morning I was checking for any potential vacuum leaks and bringing car up to temp to see if there was any change in misfire behavior...but also now getting a pending P1340 code. Believe this means cam timing adjustment issues potentially?

A couple of suggestions: 1. Ask here for a competent M96 Indie in your area. His diagnostic time could save you $$$$ 2.Get Durametric to know the details of the fault codes. If you suspect some coils - replace them all. But be prepared for 'while you are in there' issues like spark plug tubes+O rings + plugs.There ar lots of other things to observe/check. Read a lot on the M96 .Don't think it is just another car engine. It will bite you. Think of it as a helicopter engine and be prepared for lots of learning.Then see 1. above - often cheaper in the end. Oh and one word to be wary of "Deviation" -see 2. above.

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Excellent point on finding a good indie...I have been referred to R&D Automotive in Albany...but I would like to hear from folks in the Albany, NY area on any references. I did order coils and plugs as well as cam position sensor from Pelican. I see in records a recent plug tube and o ring change...but nothing on coils...so to rule those out I will replace all as well as plugs. Seems odd that three may go at once and on one bank...so with the pending P1340 I thought the cam position sensor was a good step to try as well and even if not the culprit at least I will have a just in case spare...

CAM sensor ? Do you mean CRANKSHAFT ? The Cam sensor seldom seems to fail. The Crankshaft Position Sensor is a more likely culprit to fail when hot.It is very difficult to r&r the CAM sensor unless you also r&r the AOS ,which is also awful - but your Indie knows all this ! Check for oil in the spark plug tubes anyway. Misfire codes on just one Bank - Vacuum leak there? Are the Lifters ticking on that Bank?

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Once you get into misfires that prevent normal operation I think you're best served by stopping driving & waiting until you expect it to be ok (ex. after new plugs & coil packs are installed). Seeing cam deviation is not good and further reinforces the ECU's message that something is off mechanically. I would stop driving at all & flatbed it to the garage that can properly fix it. AAA is a good resource to have.

Yes, forget about coils and MAF, you have a mechanical issue in bank 1. Camshaft timing is off too much and you need a Durametric to diagnose it further. Physical inspection of cam timing is also needed. Should try not to drive it again to avoid damage.

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Didn't have the misfires but I had the P134(1) code (pending) from my 2002 Boxster when its engine was behaving like the engine in your car. Turned off the engine and upon restart all was well and drove it 30 miles home. Next business day got the car in the Porsche service department and tech diagnosed the problem as a VarioCam solenoid/actuator failure (with the Boxster engine one can't distinguish between the two when it comes to not working right) and both were replaced. Asked tech about the other bank's solenoid/actuator should they require replacement and he said no error codes, no symptoms, no signs of any problems, not they do not need to be replaced so they were left alone. 60K+ miles later engine still running just fine. Other bank's solenoid/actuator is original and has covered over 315K miles. While my Boxster engine didn't misfire I observed the fuel trims were all over the map. Mentioned this to the Porsche tech when I dropped off the car and he said this is normal. It arises because the cam is not positioned where it would be -- advanced or retarded as it should be -- the oxygen sensor readings on that bank are wrong. The DME adjusts fueling to try to get the desired oxygen sensor readings but because the problem is a mechanical failure readings will not hit the desired targets and the DME will eventually adjust the fueling too far and misfires are the result. Best to arrange to flat bed the car to a qualified shop for a professional's diagnosis and repair.

There are simple tests on Renntech to verify the Solenoid resistance and the integrity of the solenoid wiring harness. These tests are not intrusive but they are time consuming and demand a methodical approach. Before you dismiss it, just price a replacement Actuator !The solenoids are comparatively cheap at about $500 ! And then there is the R&R If you want help with Actuator/Solenoid testing and R&R , probably better to start a separate thread ? It is not for the feint of heart https://www.renntech.org/forums/tuto...d-swap-in-car/

Thank you all very much for helping out here....I'm already learning a lot. I am a long time car guy and have a pretty sizable background in working on my own cars, but I also know that this is significantly more complicated and the penalty for taking the wrong step could be very pricey. I already have an appointment with R&D Automotive on Tuesday...they were going to look over the car after my purchase...but I'm going to call them tomorrow and see if I should wait until after I put in the new coils (those won't arrive until Thursday), or load it in the trailer and bring it down to them on Tuesday anyways. I'm definitely not driving it...I have however started it a couple times. I did find a vacuum leak...on the drivers bank at the intake manifold vacuum port (part #99611015152). It was wobbling and shooting a little MAF cleaner at it when idling raised rpms a hair. Also it is much warmer today (around 65) and I stated the car in garage...still a hair rough on idle...but no codes after letting it idle from cold idle to warm idle. Will keep folks posted as II'm hoping that whatever it is I'll be able to help others down the road...but may be delayed a few days depending on shop visit, coils etc...and while I don't think coils, plugs and the replacement vacuum port will fix it...they are items that need to be replaced anyway for peace of mind and help isolate the root of the true problem!

So an update...the local Indy shop did the sam position sensor replacement and verified that the variocam actuator is working and physically inspected timing...and it appears timing is off. They are saying could be slack in chains, pads/tensioners, or possibly IMS (even though it is an LN retrofit). They are going to removed covers in next couple days, but not looking too great right now.

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Yup, that's what the code complains about. Hopefully they will check the oil and oil pan for debris.

OP.Suggest you discuss your 'while you are in there' list to make virtue from necessity. The Indy confirms your Cam Sensor was defective? Really? If so keep the one they removed for bench testing

Hi all-- So wanted to provide an update and HOPEFULLY this issue is now in the rear view mirror. I picked up the car yesterday from the shop, and have enough miles on it that it was able to be inspected. Knock on wood... So a bunch of things transpired since last update. But the long and short of it is that both actuators seem to have been on their way out. Operating sometimes, not responding at all sometimes and sometimes being "lazy". Early on we replaced both cam position sensors (both banks) to no avail. Initially a smoke test (done when over 50 degrees) showed no vacuum leaks...but when car was below 50 degrees a subsequent smoke test showed several vacuum leaks. Once solved that stopped the misfire codes, but we were still getting timing codes. Outer pads on the variocam actuators looked OK (not great) but inners were really worn. That couple with the intermittent nature of actuation and release we ended up replacing both actuators. Photos of the parts replaced can be found at http://www.photoplace.com/Cars/2000-...-2017-18-work/ So hopefully this long and drawn out journey is ending...my early porsche ownership experience has not been great. Now tucked away in the garage until salt off the roads for a more extended drive. Pinion bearing is also giving up the ghost so a rebuilt transmission (or good used one) will be in order next. If anyone has a lead there send it my way!

Interesting - good Photos. I guess that's all the little black pieces you see in your oil filter over time. What mileage/ age is your car out of interest ?

Cheap 996's can be expensive...Glad you got it sorted out!

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Car has 148k on it now...engine was refreshed 30k ago but for sure nobody did anything with the actuators or pads then!

Just out of curiosity, and not to poor salt in the wound, but how much did all the work cost? Also, if you know, about how much was it to have the pads changed? Thanks!

Following up on this ^^ question as well??

Subscribed!

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Would a PPI have revealed anything like this?

Interesting question. In my case a general knowledge of other engines was of little value. An M96 expert who has listened to hundreds of 'ticking' M96 engines and chased many Fault Codes. would have been most likely able to pinpoint the issue. And give a quote for fixing it ! At work we seldom work on Porsches. None of us would do PPI on a Porsche. But such prudent modesty does not deter others :-). My conclusion is to find and cultivate a relationship with an M96 guy long before you buy one. And meanwhile, enjoy driving your Miata :-)

I had this problem recently. Car was running fine and then recently heard a loud tapping/ticking sound which I thought was a bad lifter. Then all of a sudden I had a very rough idle, stalling at idle, hard to stay at stable idle once started, shaking, etc. These symptoms would be alleviated by giving the car some gas but not always. Once the car was at normal speeds, it would rev fine with no loss of power and rev freely to redline. The only issue was at idle speeds. Then the check engine light comes on and begins blinking. Thinking maybe there was an issue with the MAF, I plugged in the code reader and get P0300, P0301, P0302, P0300 codes all at once and all cylinders are on the driver side bank. WTF? I had recently replaced all spark plugs and coils only 2,000 miles ago. So I took the muffler off to take a look at the spark plugs and coils. All 3 spark plugs were loose and I could turn them with my hands! I remember not tightening these too tightly for fear of stripping and not torqueing to 22ft/lbs as well as applying anti-seize (just a dab), all of which are a big no-no looking back. This accounted for the tapping sound which I had thought was a bad lifter valve. Basically the spark plug was loose and rattling. I replaced all 3 spark plugs, torqued down to 22ft/lbs and just an extra little twist for good measure. Problem solved.