2017 Tahoe with very rough idle

[dksharp]

We have a 2017 tahoe with 155K miles on it. It began idling very rough a few weeks ago. It had bank 2 sensor 1 O2 sensor bad so I replaced it. Still not better. I ended up replacing all the spark plugs and wires. No change. Cleaned the MAS air sensor. No change. 3 mechanics have looked at it. Bank 1 sensor 1 O2 indicator was delayed so replaced that one. Chevrolet recommends changing motor mounts which are worn out. We will but not at this time. 3rd mechanic says there is a technical service bulletin that mentions a lifter issue and possible camshaft issues. This mechanic thinks one of the lobes is rounded on the cam and causing this issue. His recommendation is to trade it in. I personally think it is a vacuum leak. Does anyone have any feedback on this top or know the vacuum system well?

 

[GranPrix]

Might want to do an AFM DOD delete

 

[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.

I cannot personally assist you with your issue, but other members of this Forum much more knowledgeable than me in this area will chime in.

 

[BUCKSATH]

The injector seals go bad on the L83/L86. The let air by causing a rough idle. This can feel worse if you have a bad driver side engine mount. The miles on your vehicle would tell me that both are possible. You’ll feel a clunk in the pedal from a stop that would tell you if you have a bad motor mount. The engine jiggle is most likely the injector seals.

 

[dksharp]

Might want to do an AFM DOD delete

Is this something a professional should do? How much does it cost?

 

[dksharp]

The injector seals go bad on the L83/L86. The let air by causing a rough idle. This can feel worse if you have a bad driver side engine mount. The miles on your vehicle would tell me that both are possible. You’ll feel a clunk in the pedal from a stop that would tell you if you have a bad motor mount. The engine jiggle is most likely the injector seals.

I will check these seals. You can check it like you are checking for a vacuum leak? The engine mounts are on our list to repair $1250. Would you recommend
replacing all the injectors?