Spark plug change gone wrong

I have a 2011 5.7 Tundra Rock Warrior with 117k miles. I decided to change my spark plugs the other day and everything appeared to go smoothly, until I started it up. It now has a rough idle, and is misfiring I believe. The 4 Lo, check engine, and traction control lights are all on. I used Denso plugs that were pre-gapped to .044, so don't think I needed to do anything there.

I get codes: P0354 and P0356 among many other ones, but those happen to be the 2 Cylinders I found oil on the plugs. I moved the coils to see if the codes followed the coils, but that was not the case.

Any ideas on what to do? Thanks in advance.

 

Move the plugs around too. A few weeks ago I changed plugs and one of the plugs was faulty but visually looked fine, when the engine was under load it'd start misfiring for some reason.

 

When you say oil I assume you mean oil on the top of the plug, not the part where the spark is. If so then you could have a leaky valve cover gasket (more exactly the round seals for the tubes the spark plug/ coil pack sits inside of). If so any oil in the tube would have leaked into the cylinder. That could make it run rough. I think I would pull those two plugs and verify they aren't fouled. You could turn the engine over with those plugs out to push any oil inside the cylinder but I wouldn't start it with the plugs out. Did you notice the exhaust smoking?

 

Are they Ebay or internet prime plugs?

there are known fakes out there

 

Did you check the gap? I've bought plugs that were supposed to be pre gapped but they were off.

Also, as mentioned above, beware fake plugs.

https://www.tundras.com/threads/counterfeit-denso-spark-plugs.64225/

 

Yes, on top of the plug. Okay, thanks. That's what my brother said to do. I will do that, I did not notice any exhaust smoking.

 

They are from rock auto, denso iridium (sk20hr11)

 

This happened to me also. I changed the plugs, but forgot one thing. I failed to connect one plug wire. When I started it up the 4 wheel drive dash light was lit, and a few others. Can t remember what ones. And it ran rough as hell. I only ran engine for about 20 seconds. When I shut it off, and double checked the wires that s when I saw the one I forgot to connect. What I did was, I disconnected the battery waited for about an hour then connected the wire, and made sure they all were connected. I then re connected battery. When I started it up all was right as rain.

 

I bought my plugs off ebay. They work well.

 

Have you tried swapping in your old plugs on the cylinders you got the codes?

 

I would remove those ASAP. I bought "denso" plugs off eBay that looked real. They were counterfeit. I linked the outcome in the thread above. Mine also worked well but thank god I removed them when I did.

 

They have been in truck for a year and a half, and I ve pushed them hard. They are Genuine Toyota plugs. They came in Toyota labled boxes. I m confident they are the real thing. I do not purchase from ebay very often. Though if I do I am sure to buy from top rated sellers with over 99% positive feedback. (not to say you don t.) I m just extra carefull.

 

@ColoradoTJ you can lead a horse to water.....

 

Not everything is a scam.

 

I’ve seen enough of the counterfeit spark plug issues that the only place I’ll buy them is from the dealer’s parts counter. Then again, I wouldn’t buy a gas cap from NAPA either so I’m probably more cautious than most.

 

I bought my Stant locking gas cap from Walmart only because Toyota doesn't make one. Not much of a choice here. I kept my OEM cap just in case the Stant gives me trouble.
I thought the Toyota oil filters from Thailand were fake but then the dealer near me sold the exact same ones.

 

Since he bought them from Rock Auto I doubt they are counterfeit. From what I understand is that they aren't iridium (or not solid iridium) so when they get some use the center electrode burns away. I doubt that a counterfeit plug would give problems immediately. A defective one could but I would think that getting two defective name brand plugs would be very unlikely.

 

The fact that they sell on ebay doesn t automatically make them bad. Toyota of Glendale is in fact a Toyota dealership.

 

Yes, that is one of the first things I tried. I thought it would work, but it did not. May attempt to switch them all back. Thank you.

 

If you have oil getting in the spark plug tubes from the valve cover gasket “spark plug tube seals”.....then the oil will create problems

Maybe your Ignition coils need to be cleaned,greased with dielectric grease,and reinstalled?

Also if your plugs have oil on top of them where the ignition coils go,maybe an issue There....or a bad ignition coil?

 

So after a couple of days of trying to figure it out, I finally did. I stupidly unplugged the ECU to get to the number 8 Cylinder. I had plugged it back in, but guess I didn't get it tight enough. Runs like a Tundra should now. Thanks everyone for your input.