I have a 2015 Tahoe LT. So far I've had 4 cylinders, the transmission, and the spark plugs/wiring replaced at a cost of over $10,000. Now the dealership is telling me the catalytic converter needs to be replaced. I feel like the dealership is not being upfront with me , is not catching things it should have, etc., but I don't know enough to argue otherwise. And I very well could be wrong (again, don't know enough.) That is why I want to document what has occurred so far, what the dealership has told me and the repair work it has performed, and ask that any of you with knowledge please advise me. A couple of things:
(1) As I have stated: I don't know anything about automobile mechanics. I am admitting that up front. I am posting what has happened so far in order to get advice and help me determine if the dealership is doing all it should, if I need to ask specific questions, etc. Please don't criticize me for not having done something, for having done it the wrong way, etc. I am asking these questions because I know enough to know that it feels like the dealership is taking advantage of me. Again, I admit that. Generally, other Tahoe owners have been very helpful when I've asked for advice, but if you're just going to say I'm an idiot, etc....I understand that is your opinion, and you're more than entitled to it, but please only respond if you're actually trying to offer advice. Feel free to remark to yourself that I'm an idiot, but this has caused me a ton of stress and money, and I'm just asking that you be a decent person.
(2) Somewhat related to the above - I did not want to take my vehicle to the dealership. I have a friend who owns and runs a corporate body shop and he almost always does most of the repair work on my vehicles, but because of the extent of the work and his shop not doing transmission work, he told me I would need to take it to the dealership. I know a lot of you don't like dealerships - and again, I never take my vehicles to the dealership either. But in this circumstance I didn't have another choice.
I will try to keep this summary as brief as possible while including relevant information. Here it is:
- In December 2024, the vehicle began shaking while driving, multiple instrument lights came on, a gas smell was in the cabin, etc. I took it to my friend, he advised that because diagnostic code P0300 and P0308 were popping up, I probably needed to have Cylinder 8 and other cylinders replaced, and that I needed to take it to the dealership because he didn't have the shop space to take apart the engine. The dealership confirmed his diagnosis regarding Cylinder 8. They also advised that the transmission was slipping and needed to be replaced. Specifically, here is what the dealership said per the invoice:
"Diagnostic codes P0300 engine misfire detected and P0308 Cylinder 8 misfire detected. Transmission is slipping and fluid pump is whining. Perform compression test and fuel injector balance test. Found injector for Cylinder 8 is bad. Recommended replacement of all 4 injectors on Bank 2. Customer just wanted to replace the one that tested bad replaced one injector and reinstalled all components, re-ran fuel injector balance test with another injector testing bad. Removed all necessary components and replace the 3 remaining injectors on Bank 2. Reinstalled all removed components and re-ran the fuel injector balance test. All injectors are working as designed at this time."
So, for this initial repair, the dealership replaced all 4 cylinders on Bank 2 and performed associated work at a cost of $3,000. The dealership also replaced the transmission at a cost of $6,800. I got the vehicle back on March 7, 2025.
On March 24, 2025, while driving, the check engine light began flashing and the traction control light also came on. The vehicle was also shaking, especially while idling. I googled these symptoms and saw how bad it is when the check engine light is flashing instead of being solid. I called the dealership and told them about the engine light flashing and they referred to it as the death light or something like that. I had it towed to the dealership the next day.
On April 3, 2025, the dealership told me that the park plugs and wires need to be replaced. They specifically told me, "With it being multiple misfires and plug and wire issues, that is more than likely the issue." I tell them to replace the spark plugs and wiring. They do so at a cost of $821.66. The dealership also tells me, "Truck is ready. Your gonna need a catalytic converter or go get it cut off soon. The only code that came back was for being too rich and it is bogging down some. I would just get it cut off at a muffler shop when it gets to that point."
On April 4, 2025, I picked up the Tahoe. I immediately notice that check engine light is still flashing, the traction control light is still coming on, and the vehicle is still shaking while idling. I tell the dealership. They tell me, "Gotta be the converter. Go get it cut off."
The paperwork the dealership gave me for the spark plug/wiring repair states: "Replaced spark plugs and wires as starting place due to spark plugs being fouled out. Test drove vehicle and check engine light returned with a fuel trim code and misfire code. Live data showed all cylinders on Bank 2 with misfires and rich fuel mixture. Recommended replace catalytic converters due to blockage in exhaust flow on Bank 2 causing fuel trim reading to be rich."
So that is where I'm at so far: I've replaced all 4 cylinders on Bank 2, the transmission, and the spark plugs/wiring. The vehicle still has a check engine light that is flashing, and the dealership is now telling me to replace the catalytic converter or have it cut off and replaced.
The dealership has offered to let me speak to the mechanic, but I don't know what questions to ask. Any advice/thoughts are very much appreciated. And if you need any more details or have any other questions I will do my best to answer. To date my repair costs are $10,706.21.
(1) As I have stated: I don't know anything about automobile mechanics. I am admitting that up front. I am posting what has happened so far in order to get advice and help me determine if the dealership is doing all it should, if I need to ask specific questions, etc. Please don't criticize me for not having done something, for having done it the wrong way, etc. I am asking these questions because I know enough to know that it feels like the dealership is taking advantage of me. Again, I admit that. Generally, other Tahoe owners have been very helpful when I've asked for advice, but if you're just going to say I'm an idiot, etc....I understand that is your opinion, and you're more than entitled to it, but please only respond if you're actually trying to offer advice. Feel free to remark to yourself that I'm an idiot, but this has caused me a ton of stress and money, and I'm just asking that you be a decent person.
(2) Somewhat related to the above - I did not want to take my vehicle to the dealership. I have a friend who owns and runs a corporate body shop and he almost always does most of the repair work on my vehicles, but because of the extent of the work and his shop not doing transmission work, he told me I would need to take it to the dealership. I know a lot of you don't like dealerships - and again, I never take my vehicles to the dealership either. But in this circumstance I didn't have another choice.
I will try to keep this summary as brief as possible while including relevant information. Here it is:
- In December 2024, the vehicle began shaking while driving, multiple instrument lights came on, a gas smell was in the cabin, etc. I took it to my friend, he advised that because diagnostic code P0300 and P0308 were popping up, I probably needed to have Cylinder 8 and other cylinders replaced, and that I needed to take it to the dealership because he didn't have the shop space to take apart the engine. The dealership confirmed his diagnosis regarding Cylinder 8. They also advised that the transmission was slipping and needed to be replaced. Specifically, here is what the dealership said per the invoice:
"Diagnostic codes P0300 engine misfire detected and P0308 Cylinder 8 misfire detected. Transmission is slipping and fluid pump is whining. Perform compression test and fuel injector balance test. Found injector for Cylinder 8 is bad. Recommended replacement of all 4 injectors on Bank 2. Customer just wanted to replace the one that tested bad replaced one injector and reinstalled all components, re-ran fuel injector balance test with another injector testing bad. Removed all necessary components and replace the 3 remaining injectors on Bank 2. Reinstalled all removed components and re-ran the fuel injector balance test. All injectors are working as designed at this time."
So, for this initial repair, the dealership replaced all 4 cylinders on Bank 2 and performed associated work at a cost of $3,000. The dealership also replaced the transmission at a cost of $6,800. I got the vehicle back on March 7, 2025.
On March 24, 2025, while driving, the check engine light began flashing and the traction control light also came on. The vehicle was also shaking, especially while idling. I googled these symptoms and saw how bad it is when the check engine light is flashing instead of being solid. I called the dealership and told them about the engine light flashing and they referred to it as the death light or something like that. I had it towed to the dealership the next day.
On April 3, 2025, the dealership told me that the park plugs and wires need to be replaced. They specifically told me, "With it being multiple misfires and plug and wire issues, that is more than likely the issue." I tell them to replace the spark plugs and wiring. They do so at a cost of $821.66. The dealership also tells me, "Truck is ready. Your gonna need a catalytic converter or go get it cut off soon. The only code that came back was for being too rich and it is bogging down some. I would just get it cut off at a muffler shop when it gets to that point."
On April 4, 2025, I picked up the Tahoe. I immediately notice that check engine light is still flashing, the traction control light is still coming on, and the vehicle is still shaking while idling. I tell the dealership. They tell me, "Gotta be the converter. Go get it cut off."
The paperwork the dealership gave me for the spark plug/wiring repair states: "Replaced spark plugs and wires as starting place due to spark plugs being fouled out. Test drove vehicle and check engine light returned with a fuel trim code and misfire code. Live data showed all cylinders on Bank 2 with misfires and rich fuel mixture. Recommended replace catalytic converters due to blockage in exhaust flow on Bank 2 causing fuel trim reading to be rich."
So that is where I'm at so far: I've replaced all 4 cylinders on Bank 2, the transmission, and the spark plugs/wiring. The vehicle still has a check engine light that is flashing, and the dealership is now telling me to replace the catalytic converter or have it cut off and replaced.
The dealership has offered to let me speak to the mechanic, but I don't know what questions to ask. Any advice/thoughts are very much appreciated. And if you need any more details or have any other questions I will do my best to answer. To date my repair costs are $10,706.21.
