Has anyone ever experienced jolting around 4000 RPM then all good beyond to 7000 RPM?
I own a stock WRX 2000 Impreza and trying to nail the issue. I'm tippping it could be an Air Flow Meter issue or Mass Air flow meter. Have done a major service on it and still doing it.
Any ideas or have ever heard of such an issue?
I have pulled the AF meter out and given it a good clean as best i can. After purchasing the car the air filter was wrotten so replaced with a performance filter. There was a lot of black dirt in there too.