2025 Tahoe 6.2-liter Z71 engine light flashing, stuttering engine

[Joseph Garcia]

Welcome to the Forum from NH.

Lots of knowledgeable folks here who freely share their knowledge, experiences, and perspectives. Knowledge is power.

I hope that you will become a participating member in the Forum's discussions.

Pics of the truck, please.

You are already receiving sage advice from the knowledgeable folks on this Forum.

 

[jfoj]

Flashing SES/CEL/MIL usually means misfiring, which appears you felt in the vehicle.

Some common causes are fuel injectors, ignition components, fuel delivery and even the low pressure Fuel Pump Control Module being intermittent.

The dealer or anyone with an OBDII tool should be able to obtain the OBDII codes and what is really KEY is the Freeze Frame Data. Even if the vehicle is new and under warranty, EVERYONE needs their own OBDII scan tool. A reasonable option is OBDFusion for your phone, $10 max. The buy an interface like this on Amazon for $32 or less if there are discounts - https://www.amazon.com/gp/product/B073XKQQQW/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

This way you can gather your own data, sometimes helpful for the repair shop and will allow you to know what may be the culprit.

I keep an interface in ever one of my vehicles.

 

[WalleyeMikeIII]

Next time the CEL is flashing, hit OnStar and ask for the remote diagnostics. Hopefully this will get you the codes w/ what cylinder is MisFiring. That said, I’d think the history code would give the actual cylinder or cylinders that are misfiring.

 

[ChevyFan47]

Probably 25 different things that could cause that condition. Is it always the same cylinder mis-firing?

It is "cylinder 4," whatever that is. They removed and relocated the spark plug, coil and plug wire to different cylinders. Then test drove it and found that it stayed on cylinder 4. They did some other stuff like inspecting lifters and camshaft and valves. The "valve sets" were not sealing. They installed a cylinder head and cleared codes and test drove it. Worked fine. Next day I got and the misfire was back.