Spark Plug Questions

[ellev8or]

92 PA
134,000

For almost a year now I've been using iridium spark plugs because the AutoZone manager stated that my engine can use them, and other reasons he gave. Less than a week ago I've received a code 41 and learned that it could be four different things; ignition coils, cam sensor, bad fuel economy and I can't remember the last one.

I had AutoZone check ignition coil module, it was good. They checked the coils and they were reading low compared to the new coils he checked against my coils. Is it possible the coils are reading low because of the iridium plugs? If so, should I go back to the copper or platinum plugs and keep the same coils, or it doesn't really matter because the coils are bad?

AutoZone stated that I should go back to using the copper plugs because my car's computer is not recognizing the iridium plugs, which makes sense, or does that matter? I was told that the iridium plugs spark hotter and gives more power to the engine, is this so?

Thanks in advance.

[jdl]

As far as spark plugs, I'd follow the manufacturer recommendations. Give me a second and I'll look up the specs. I don't know about different spark plugs. For the buick PA, 3.8L non turbo, acdelco says standard spark plugs, ac 41-601. I didn't check out the pa ultra.

Code 41 is for the cam sensor, but, the cam and crank sensors share ref voltage and ground. So a problem with one sensor or circuit could effect the other sensor.

[Tech II]

Do these guys make this up as they go along?

For almost a year now I've been using iridium spark plugs because the AutoZone manager stated that my engine can use them, and other reasons he gave. Less than a week ago I've received a code 41 and learned that it could be four different things; ignition coils, cam sensor, bad fuel economy and I can't remember the last one.

They really said that? Code 41 is caused by: Bad cam sensor, deteriorating or lost magnet on the cam sprocket, bad harness connection at cam sensor, bad harness connection at ICM, bad wiring between the cam sensor and the ICM, bad ICM, bad harness connection at ECM, bad wiring between ICM and ECM, or a bad ECM.....It has nothing to do with coils...no, I take that back, if you had a shorted coil/ignition wire/plug, that could take out your ICM, but you would definitely have a bad misfire....

I had AutoZone check ignition coil module, it was good.

I have no faith in their testing ICM's out of the vehicle.....they are not exposed to the load/heat of the vehicle,,,,,

They checked the coils and they were reading low compared to the new coils he checked against my coils. Is it possible the coils are reading low because of the iridium plugs? If so, should I go back to the copper or platinum plugs and keep the same coils, or it doesn't really matter because the coils are bad?

I read your other post, and the ohm readings you were getting are OK... however, you can have a good ohm reading and still have a bad coil....best way to check the output of a coil is with a spark tester...


AutoZone stated that I should go back to using the copper plugs because my car's computer is not recognizing the iridium plugs, which makes sense, or does that matter? I was told that the iridium plugs spark hotter and gives more power to the engine, is this so?

They said the ECM is not recognizing the iridium plugs? Then maybe they should be formally introduced......plugs have nothing to do with it....but you should use the OEM plugs that originally come with it....but you should be able to use either one, just make sure they are A-C/Delco, and not aftermarket......The iridium plugs were a 100,000 mile plug....the copper ones were a 36,000 miles plug.....more power? you wouldn't notice it.....

It seems to me you are not complaining about a misfire, just the code 41......if there is no misfire, coils, wires, and plugs are not your problem....

[ellev8or]

Where is the cam sensor located?

I will be going back to the copper A-C/Delco.

Thanks

[maxwedge]

Tech11 again on the money. I would not change the Iridium plugs they are the best performing longest lasting plugs out there. No more Autozone for diagnostic advice!! Actually AZ's online shop manual has some pretty good basic stuff, go to autozone.com/repair guides they will have the how to on the cam sensor.