I'm going to look at a 95 sc300 with a 5 speed r154 transmission swap and the owner said a transmission fault code was normal and nothing to worry about. I was wondering if this is in fact nothing to worry about and if there are any other typical modifications I should keep an eye out for as he said the previous owner had installed a new engine while it is still a factory 2jz ge engine. I'm a bit concerned about how many people have been into this car. Thanks in advance

 

I would check the codes and report them back or look them up, dont take their word for it.
it could be an auto code if it was swapped to manual, or it could be something else like speed sensor or something. If everything else checks out and it runs and drives goof then maybe, if those are the codes they aren't that hard to get around.

 

Transmission codes are not normal. Even with R134. If it's something minor, dont worry about it though.

 

Sounds like an auto>5-speed swap. Drive it. Manuals show their faults fairly quickly.

 

Yes they do, more so in reverse and 1st gear. IMO.