VW Jetta / Bora MKIV 1998 Euro,1999.5 US -2005
I have a 2002 vw 1.8 turbo jetta with 190,000.
My car was doing fairly good until I added some of gas treatment stuff (I think STP). Since then, it has been a lot louder and sounds like its misfiring. And the engine light came on.
The STP gas treatment may or may not done it ... IDK...