JPR10

Reviving this thread. OP, don't know if you're still on here, but did you ever figure it out?

I'm dealing with poor fuel economy with my 525. I've changed my air filter and have done VANOS seals.

I've also used CRC MAF cleaner to clean my MAF... What else should I be doing? Plugs? O2 sensors?

I'm not sure if they've ever been changed...