Fbkc, flkc

My car is a 2007 wrx, I’m having some feedback knock and fine learning knock under slight acceleration around 2500rpm and 3k rpms.

Hello, how can we help?

Please tell us more about the vehicle i.e. transmission type, specific modifications

2007 Subaru wrx

5spd manual trans

pretty much stock with a big top mount intercooler

Jay,

Are you still on the stock tune? If no, what reflashing package are you using to tune?

I am using romraider to log, ecuflash to adjust parameters and flash to car

Jay,

What does "pretty much stock" mean? What is not stock?

Ok so now I have a cat less invidia downpipe, ngr bov and a big tmic. I’ve been following the modules for the base map, maf scaling and so on. Now I keep getting -5.60 fbkc. I’ve retarded timing with no change.

Jay, the BOV will totally screw up engine operation because this is a MAF based vehicle. That screws up measured air mass, which is how the ECU determines not only how much fuel to inject, but how much engine load is present, which is the primary load axis for ignition timing and cam phasing. Have you tried this with the stock bypass valve installed and recirculating?