Camry misfiring on highway

[53' Stude]

This morning on way to work, my 09’ Camry started misfiring around 58-60mph, but didn’t flash the check engine light. Once I hit 60 and above it flashes. Stopped on side of highway for bit, didn’t see anything visually wrong or amiss under hood. Idling it doesn’t shake or act like it wants to misfire or Roman rough. Anything I should check for? Replaced spark plugs with DENSO ones from member ThirdEye about 10k ago.


Thank You in advance

 

[javacontour]

This morning on way to work, my 09’ Camry started misfiring around 58-60mph, but didn’t flash the check engine light. Once I hit 60 and above it flashes. Stopped on side of highway for bit, didn’t see anything visually wrong or amiss under hood. Idling it doesn’t shake or act like it wants to misfire or Roman rough. Anything I should check for? Replaced spark plugs with DENSO ones from member ThirdEye about 10k ago.


Thank You in advance

Get the codes and see which cylinder(s) are misfiring.
If only one, swap the plug with one cylinder and swap the coil with a second.
If the problem moves, it's likely the component you placed in that cylinder. If the problem remains the in the same cylinder it's either the wiring to the coil or a mechanical / injector issue with the cylinder.

 

[Leo99]

My guess is a coil. Do what Java says.

 

[LazyDog]

Does the car have an EGR???

 

[Rand]

are you sure they werent fake sparkplugs sometimes the fake ones wear out VERY FAST.

 

[53' Stude]

are you sure they werent fake sparkplugs sometimes the fake ones wear out VERY FAST.

These are legit. I crossed the DENSO # and it is a Toyota replacement. I don’t think ThirdEye would lie to me

 

[Rand]

These are legit. I crossed the DENSO # and it is a Toyota replacement. I don’t think ThirdEye would lie to me

I'm not familiar with this person where did the spark plugs originate? Not throwing shade.

but with possible fakes coming from rockauto, and many online sellers caution is warranted.

Not saying its likely just something to consider.

I'd start with a code reader determine which cylinder.
then swap one thing only. spark plug or coil.

Does this engine still use wires? or coil on plug?

 

[Graham Piccinini]

How many miles on your vehicle? My guess would be the ignition coils. Swap with another cylinder to see if issue follows the coil, or just replace all due to age/miles, if they're original. Doubt it's the spark plugs.

 

[53' Stude]

How many miles on your vehicle? My guess would be the ignition coils. Swap with another cylinder to see if issue follows the coil, or just replace all due to age/miles, if they're original. Doubt it's the spark plugs.

It has 198k on it

 

[53' Stude]

I'm not familiar with this person where did the spark plugs originate? Not throwing shade.

but with possible fakes coming from rockauto, and many online sellers caution is warranted.

Not saying its likely just something to consider.

I'd start with a code reader determine which cylinder.
then swap one thing only. spark plug or coil.

Does this engine still use wires? or coil on plug?

I believe he had the plugs for a vehicle he sold. He offered them to me and a Toyota OEM valve cover gasket. The plugs that were in car when I changed them were NOT even close to correct ones. Here are those

 

[Rand]

I believe he had the plugs for a vehicle he sold. He offered them to me and a Toyota OEM valve cover gasket. The plugs that were in car when I changed them were NOT even close to correct ones. Here are those

That still doesnt rule out them being online bought fakes.

It wouldnt hurt to pull the misfiring one and give it a visual inspection. But I also doubt its the plugs.
200k a coil or wire seems more likely.

 

[JeffKeryk]

I have been burned 3 or 4 times on fake NGK plugs from Amazon. Pull one or two and look at the electrode. The fakes I got had worn, rounded tips in less than 40K.

It happens and is maddening. Good luck.

 

[53' Stude]

That still doesnt rule out them being online bought fakes.

It wouldnt hurt to pull the misfiring one and give it a visual inspection. But I also doubt its the plugs.
200k a coil or wire seems more likely.

I will do that. I don’t know where BITOG member ThirdEye bought the plugs, but ThirdEye is a stand up member here. That is all.

 

[53' Stude]

I'm not familiar with this person where did the spark plugs originate? Not throwing shade.

but with possible fakes coming from rockauto, and many online sellers caution is warranted.

Not saying its likely just something to consider.

I'd start with a code reader determine which cylinder.
then swap one thing only. spark plug or coil.

Does this engine still use wires? or coil on plug?

Cool on plug

 

[mk378]

When the customer says "it can't be X," X should be the first thing you check.

 

[Trav]

Do an exhaust back pressure test after checking the coils. This is also a symptom of a clogged cat.

 

[The_Eric]

200k, have you ever replaced the coil boots? Have seen plenty go bad and leak voltage.

 

[53' Stude]

Do an exhaust back pressure test after checking the coils. This is also a symptom of a clogged cat.

New cat converter I replaced with Toyota OEM last July

 

[53' Stude]

200k, have you ever replaced the coil boots? Have seen plenty go bad and leak voltage.

I have new Toyota OEM coils with boots. Haven’t replaced coils or diagnosed yet as I’m at work

 

[B1974]

This is also a symptom of a clogged cat.

I second this. It happened to me once about 20 years ago.