Misfire and Throttle codes after plugs and air filter replacement – Diagnostic Network (2024)

AiDN AI Assistant

This is a reply from an experimental AI-powered advisor. It is important to exercise caution, verify information from multiple sources, and make informed decisions based on the prevailing circ*mstances.

Jordan, it seems like you've covered a lot of bases already, but let's address a few potential issues: - Coil Damage: Given the difficulty you experienced removing the coils and the subsequent misfire issues, it's possible that the coils were damaged during removal. Resistance and continuity tests on the coils can help confirm their integrity. If they show any signs of damage or…

Howard Mechanic

Did you torque the spark plugs to spec? I used to be an import tech and found out quickly that the spark plugs have to be torqued to spec and then indexed properly or they will misfire. Throttle codes are probably set because of the misfire, in order to protect the engine and catalyst.

Jordan Owner/Technician

So Prodemand showed a torque for 24 FT LBS, I had no service information elsewhere I believe ALL DATA said the same. New plugs 24ft lbsUsed 19 Ft lbs

Howard Mechanic

That’s a start. I’d take a look through the r&r section to see if the plugs require a certain number of degrees turn after the initial torque. I’ve had some Mercedes that will show a torque in the “specification” tab, but not the 70 something degree turn you needed to properly index the spark plug

Jordan Owner/Technician

Prodemand and ALLDATA give no helpful information other than the torque spec no R&R First step on both is remove ignition coils Then spark plug torque spec..

Howard Mechanic

Okay. If there’s no extra degrees turn, then as others have mentioned, I would examine the plugs for cracks in the insulators. I have both cracked spark plugs and have had spark plugs that have been cracked fresh out of the package.

Obie Technician

Silly questions, but you did not put anything on the plug threads did you? And are plugs the exact duplicates of the old ones? Dealers make mistakes like everyone else.

Jordan Owner/Technician

Parts numbers match and plugs match identically yes.

Hollis Technician

Jordan, I believe what Obie was asking in reference to putting anything on the spark plugs, like anti-seize, can/may cause misfires.Most modern/quality spark plugs threads have a special coating/treatment to reduce corrosion and seizing without compromizing electrcal conductivity.

Jordan Owner/Technician

No sir, nothing was placed on the threads.

Hollis Technician

Did you remove the spark plugs of the affected cylinders and inspect the ceramic insulators for cracks?IIRC, the majority of plug sockets for those are 12 point, with no rubber cushioning inside, it's easy to crack an insulator with that type of socket.

Jordan Owner/Technician

That may be the case. I used the BMW spark plug 12pnt socket I am going to remove them all today and check resistance.

Hollis Technician

Insulator cracks examples.google​.​com/search?sca_esv…

Robert Technician

Just a thought did you check the gap I show 0.028 3.0 6 cylinder, I gapped a Jeep wrong once that thing wouldn't even run dealer plugs.

Jordan Owner/Technician

I checked them compared to the OE plugs, it was fine. I spoke with OPUS IVS and Rich confirmed torque spec was 23 NM…..Prodemand stated 24 FT LBS… So i definitely over torqued them. I'm not overly surprised Prodemand stated incorrect values for this type of vehicle. Does anyone know other than the factory Porsche software, where I can find proper torque valves for this type of vehicle and…

Hollis Technician

Qualifier Min. (Ft. lbs) Max. (Ft. lbs) New Spark Plug 17 17 Old Spark Plug 16 16 Motor Spec.While it's always a good practice to follow OEM torque specs, it's good to develop a “feel” for a specific type of fastener, spark plug, and the application, ie aluminum, steel, and take into consideration, thread length, and so on.Coworker cracked a CVT fill plug hole in the trans body, he…

Jordan Owner/Technician

I think it’s time I sign up for Motor as well as everything else… my Ultra has Motor functions along with ShopMonkey.

Hollis Technician

Have you considered Identifix Direct Hit? What they haven't got published, you can request and they're pretty quick to get back to you.It's got Motor and other content providers (if that's the correct term). I haven't used or explored other SI services in years, we've had IDfix for quite sometime, and OEM subscriptions. We only work on 4 makes, so OEM cost is justified. Most OEM SI…

Jordan Owner/Technician

I have Solera Identifix yes. I haven’t used it on euros very much as I figured it was more of a domestic tool. Is that incorrect? Do they have good info for euro makes? I have IdentifixALLDATAProdemand Opus ivs/Drive Pro & Bluebox Elunity​.​ca

Hollis Technician

All I work on is Subaru :O)I'm not sure how much info they have for Euros, they just don't seem to publish a lot, so if you're in need, submit an info request and they will provide what they have.

Cedric Owner/Technician

The Porsche PIWIS manual states as ProDemand 32Nm (new) and 25Nm (used).I would be curious to know where “OPUS IVS and Rich” got their specs from.

Jordan Owner/Technician

Cedric,So I did torque them correctly then… So Hollis Davis has incorrect specs now from MOTOR? This is very conflicting. If I torqued them correctly, maybe the vibration of my electric rachet cracked the insulators..?

Obie Technician

Jordan, you may have something with the electric ratchet damaging the plugs!For I don’t know how long I only used power tools to remove fasteners on engines or spark plugs. Reinstalled both by hand, always. I felt the ability to feel problems with fasteners and not shocking sensors or spark plugs was worth the effort.

Cedric Owner/Technician

I am too scared to use an air or electric ratchet for any spark plugs…

Hollis Technician

Sorry, Jordan. I was merely posting the specs that Motor had listed.Even the OEM SI has incorrect information sometimes. I also mentioned this in a previous reply above.“Most OEM SI sources will have short term subscriptions you can purchase and download at reasonable cost.”I understand the position you're in and it's an expensive lesson to learn, you'll get through it, we've all been…

Pierre Owner/Technician

IMO, I'd order another set of OEM Plugs and torque them to the manufacturer spec.

Jordan Owner/Technician

Yes that is what I am doing along with all new coils as I know 1 got damaged in removal. I will update once we get parts in.

Liam Owner/Technician

I've definitely seen these and the earlier Porsche 911's throw more and more cylinder misfire codes the longer they are left running unevenly especially once an injector is shut down for cat protection, so you may have only 1 bad plug or coil.I have diagnosed misfires on these shortly after the official dealership have carried out a service and spark plug install only to find 1 or more…

Jordan Owner/Technician

Liam,That was absolutely fantastic! Thank you so much for all of that information. I definitely appreciate that and agree. I will try the brake cleaner trick. I wonder if I magnetized the actual electrode rod. And put magnetic powder like magna fluxing a cylinder head would show? I only have the BMW 12 point spark plug tool…Is there a part number for the proper tool? I'd really like to not…

Hollis Technician

Platinum is nonferrous, interestingly, iridium has magnetic properties (see article link below)As for spark plug insulator cracks, most are visible to the naked eye, for sh_ts and giggles, a dye penetrant and developer should suffice for crack viewing. (reminds of a joke involving flour) :O)photon-science​.​desy​.​de/news__events/n….

Obie Technician

That is a pretty good joke!

Jordan Owner/Technician

Hello, got it yes didn’t even think of that. And yeah okay I’ll try that! ***Edit had to google the Joke*** pretty bold ha!

Liam Owner/Technician

The spark plug socket listed as the Porsche Special tool was originally the Snap-On S9714MK with rubber insert but that has changed to VAS 6919 (Part Number ASE… ) which is actually a Hazet 4766-2 spark plug socket with the spring retainer style. I’m not sure if there was any particular reason for this change, maybe the rubber insert was an issue. I believe the Hazet socket is…

Hollis Technician

I've got a 6 & 12 point 14 mm spark plug socket from this company. I've used them a few years now, no issues or cracked plugs. They have a good selection.kokenusa​.​com/pages/spark-pl…

Robert Technician

Liam brings up a good point crazy PCM starts ID the wrong cylinders also coil spike effecting TAC p2176 is right in the ballpark.

Jordan Owner/Technician

Hi Robert,Are you suggesting the coil spike could be causing my throttle code?

Robert Technician

Sure the PCM doesn't like secondary spiking with TAC codes sometimes no scanner communication. I haven't seen 1276 but 1270 Rev limiter and forced idle 1211 I think,stress them coils out if possible tests

Jordan Owner/Technician

Hello DN,Just wanted to let you all know I replaced the plugs and all coils. Used hand tools, torqued to 24 FT LBS as per Specs.. All is good!Thank you all, I learned a lot of lessons on this vehicle..Funny enough I did plugs on a VW TIGUAN yesterday… Ran them in with my electric rachet (just to see) as I always have done. Didnt torque them, just went for “feel” as one member had mentioned…