Engine sputters when trying to accelerate

Could be spark plugs breaking down. I would start with basic tune up parts.

Roy

It is a five speed manual. A tune as already been done.

Okay.

Are there any codes or is the check engine light on?

A common cause for this is the injectors. They get dirt inside and the spray patterns are not correct. Additives have no effect on cleaning. You need to have someone use a direct injection of injector cleaner to break up the carbon deposits.

Roy

https://www.2carpros.com/articles/how-to-test-a-fuel-injector

I thought that may be it. Thanks so much.

You are welcome.

Always glad to help.

Roy