Question for mechanics RE: spark plugs

I'm far from a mechanic. I just watch videos on YouTube or find instructions online then try to do it on my own sometimes. 

 

So so today I replaced the Spark Plugs on my Dakota. I bought 8 spark plugs cause it's a V8 (4.7L Magnum) and to my surprise my truck actually has 16 spark plugs. I had no clue that Magnums had 16 but apparently starting in 08 they had 2 per cylinder. I thought only Hemi's had 2 per. 

 

So anyway, I replaced the 8 spark plugs that are on the top of the engine and the other 8 are underneath, very tricky to get to. I'll do those next week. But after I replaced the top 8 I was driving and I noticed my check engine light is on. Did I fuck something up or is it just on maybe cause it senses I have 8 new and 8 that are 103k miles old? 

My truck drove for 40 minutes just now and it was fine but the check engine light was on. What a pain. I really don't want to have to remove all those plugs and redo them

they produce sparks

 

 welcome

The OBD system isn't intelligent enough to sense that you have new spark plugs or not, just if the system is functioning correctly.   

The best thing to do is pull the codes from the PCM and go from there. If it wasn't on before it will likely be something related to the work you did. 

Did you use the right plugs? is everything seated?

is it misfiring?

On my Subaru if I use anything other than NJK it will sometimes misfire

have autozone pull the code

Did you check the Spark Plug Fluid?

Chimonos Revenge - Did you check the Spark Plug Fluid?

What he said.



The light coming on after you changed the plugs almost certainly means that it's related to what you did.

Wrong plugs, not in all the way, loose wires, etc, etc.

I agree with the guy who said to get the code pulled at AutoZone...

I bet there's some kind of imbalance between the new and old plugs causing some crazy misfire codes.

One of your wires maybe not on tight

It could be something stupid like one of the gaps being fucked up on the plugs causing a misfire

Sogsteel -

It could be something stupid like one of the gaps being fucked up on the plugs causing a misfire

I used my Uncles gap tool to do them all 

Did you put the wires back in the same position?

Auto parts stores will do a code read for free.









Oh... And like someone else said -- check that spark plug fluid. It should really be drained, flushed, and refilled with every tune up. I would go with synthetic. It's worth the extra few bucks.

Thanks for the responses gentlemen. Seems like all I had to do was disconnect the battery then reconnect it and now the check engine light is off. I read somewhere that doing so resets some code or some shit 

onepunchJD - Did you put the wires back in the same position?

Auto parts stores will do a code read for free.









Oh... And like someone else said -- check that spark plug fluid. It should really be drained, flushed, and refilled with every tune up. I would go with synthetic. It's worth the extra few bucks.

I think I figured it out. I'm getting new tires today too so I think I'll have them check it out just in case 

Vegito Blue -
Sogsteel -

It could be something stupid like one of the gaps being fucked up on the plugs causing a misfire

I used my Uncles gap tool to do them all 

It will be speculation until you get codes. The other thing you can try is clearing the codes with a battery disconnection and see if the code returns. If it does then there is certainly an existing issue. 

Sogsteel -
Vegito Blue -
Sogsteel -

It could be something stupid like one of the gaps being fucked up on the plugs causing a misfire

I used my Uncles gap tool to do them all 

It will be speculation until you get codes. The other thing you can try is clearing the codes with a battery disconnection and see if the code returns. If it does then there is certainly an existing issue. 

That's exactly what I did and it seems to have worked. I'm getting new tires today so I'll have them check it out just in case 

Vegito Blue -
Sogsteel -
Vegito Blue -
Sogsteel -

It could be something stupid like one of the gaps being fucked up on the plugs causing a misfire

I used my Uncles gap tool to do them all 

It will be speculation until you get codes. The other thing you can try is clearing the codes with a battery disconnection and see if the code returns. If it does then there is certainly an existing issue. 

That's exactly what I did and it seems to have worked. I'm getting new tires today so I'll have them check it out just in case 

The light may return after it goes through a couple drive cycles. You will need to drive it for a bit

Vegito Blue - 

Thanks for the responses gentlemen. Seems like all I had to do was disconnect the battery then reconnect it and now the check engine light is off. I read somewhere that doing so resets some code or some shit 


When the light comes back on let us know what code it is and we can go from there