Engine misfiring AFTER plugs and wires replace but not before

I need help. I have a 2003 Dodge Dakota V6. My boyfriend helped me replace my spark plugs and wires. The engine was running fine before hand, and right after they were replaced. And now my engine is misfiring pretty bad. It started on my way to work and I heard a hissing noise and sometimes a clanking noise. We did have to remove the whole air filter unit to get to the plugs on the passenger side. When we replaced the the plugs and wires one at a time making sure the wires were going in the correct spots. I’m fearing the worst. With I honest cant afford financially and my job really relies on my vehicle… We dont have a code reader, so nm I dont have any codes, and of course both the mechanics in my family are not willing to help, even when I’m offering to pay. Any help would be greatly appreciated.

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It’s possible the problem isn’t related to the work you did. A hissing sound… have you ensured all vacuum lines are secured?

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Seeing that it ran fine for a little while after changing the plugs and wires.

First thing I would be checking is that the wires are still attached properly at both ends, one or more may have come off.


I have not. And I’m not entirely sure where they are on my truck.

I can try that… I’m thinking of having it towed from where I’m at now to a shop… my boyfriend says that having it towed is a was of money. But I’m terrified of cause anymore harm to it than I may already have…

I think that might be a good choice. I also think this boyfriend might not be as good with vehicle work as he thinks he is. You said your employment is linked to having transportation so let a shop fix this . You will not be the only person who has had to borrow money or use a credit card to have vehicle repair.

The part about the family mechanics not willing to help concerns me . This might be a good time to find out why.

Can you or someone look where each spark plug is located? You might need a small mirror for those on the back side of the engine. Is one loose, or screwed in at a different angle from the rest?

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My dad is going through a midlife crisis, and I believe he no longer has any of his tools… and my uncle says hes was to backed up to help, I had asked him this 3 days ago when one of the plugs was hard to get out, almost thought I was going to have to take it in to get it removed, but it finally let go, intact.

How could one bn be screwed in at a different angle? And they’re all 1/4 turn passed and tight.

Did you also replace the distributor cap and rotor?

No I did not…

The cap may have been damaged during the wire replacement.

But the hissing does point to a dislodged vacuum line.

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If one was forced in cross-threaded, it might look slightly crooked, or not all the way in. It would be subtle. If one has come out - not so subtle. Good luck and best wishes.

Is the cap and rotor the mechanism that the wires get plugged into?

With a hissing noise I would suspect that a vacuum line has been dislodged or damaged. A vacuum leak can certainly cause an engine to run poorly.

That’s assuming that you’re 100% certain beyond all doubt that there is not a plug wire crossed up.

I’m fairly certain they are. We did each plug and wire one by one. Never taking more than one plug/wire at a time.

Did you use OEM wires and plugs? Or did you buy aftermarket? Have you tried reinstalling the plugs and wires that you took out?

Is the hissing sound steady or pulsing? If it is pulsing, that would probably be a loose or cross threaded plug. If it is steady, it is more likely a vacuum line that is now disconnected at the throttle body. The throttle body is between the air filter duct and the intake manifold and it may have become disconnected when the air filter assembly was removed.

You also have a MAF sensor in the duct between the air filter and the throttle body. It may be located right next to the air filter. Often you have to disconnect the plug going to it to remove the air filter. Make sure it is plugged in and secure and that the MAF sensor is also secure.

Was the spark plug gap checked prior to installing the new spark plugs?


The possibility that the plugs were improperly gapped jumps off the screen at me. If the ceramic tip is cracked the engine might run a while but them when the tip breaks off the top of the ceramic can blow out. But that’s usually a mistake made by old DIYers using old techniques.