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Q: I have 05 audi a 6 Quattro 4.2. I sprayed the engine off one afternoon. Now I'm getting primary/ secondary circuit malfunction sho

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I recently sprayed my engine off. Next day, started it and it was missing. Hooked scanner to it and codes for po 300 random/ multiple misfire, po351 ignition coil A primary/secondary circuit malfunction and cylinder 1&5 misfire. Changed spark plugs and 1&5 coil packs. Still missing like it was. What is ignition coil A primary secondary malfunction? If you can help I would greatly appreciate it.

My car has 134000 miles.
My car has an automatic transmission.

This is a common problem with the Audi models. Generally one of the advantages to having coil packs instead of a distributor is that they are a little more water resistant, however this is a known issue with Audi in that they tend to fail at times when wet. You can also check or replace the spark plug wires as this code can also be triggered when the wires are bad or there is a faulty connection. This can also happen when there is a short in the wiring harness which could have happened when it got wet. I would suggest having a certified expert, like one from YourMechanic, come to your home to diagnose the misfiring issue and help you repair it as necessary.

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