2008 Nissan Altima; Needs Work, But Clean

Listed for sale, is this 2008 Nissan Altima S that's clean inside and out. The interior is in good condition within minimal wear and tear. The exterior is also in good condition, but does have a few scuffs and scratches. The vehicle also has the chrome wheels, and they and the tires are in good shape,
The vehicle is being priced so low because it needs mechanical work. The vehicle appears to be in limp mode, and will barely move' so it would have to be towed. However, not sure the issue. My son said he was driving when the vehicle thumped real hard, then would barely move. Not sure what the issue is, and there is no check engine code to help diagnosis the issue. My mechanic said it sounds like the throttle body, or it could be the transmission control module. My son decided to buy another vehicle; rather than fix this. However, the vehicle was driving fine up until loud thump occurred.
This is a really nice, cleaned vehicle, and it's worth fixing. Besides, it may turn out to be an inexpensive repair. Thanks!

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