How do I fix an error 17536 on a 2001 audi a4 quattro 1.8t?

Does it mean the engine needs a service?

Generally, from what I can tell from Google searching, it means that the air to fuel mixture is lean (needs more air) so there is either an air leak or a clog in the line.

I’ve looked for leaks in hoses and such, but haven’t found any.

I’ve put fuel injector cleaner through and it hasn’t seemed to help.

You know it’s bad when cars start giving errors with numbers.

It could mean nothing at all. In this case, the real indicator is performance. Is the vehicle performing well? Then save your dinero. Your mechanic does not need to make a payment on his yacht till next month.