Hi there if anyone can help would be much apreciated. I have a problem with my r33 gtst rb25 have been running power fc for over 12 months now. First tuned it in winter by the way everything else is standard bar power fc and boost controller & hi flow exhaust & also front mount intercooler after tuning car, car drove awesome no tune problems ran 7psi low boost & 13 psi high boost did not have any knock problems & afr was perfect. Had dynoed & produced 305hp at the wheels.
When summer came around knock level was a bit more active due to the extra hole that had been cut in air box & no cold air induction on air box due to intercooler pipe in the way & motor sucking in all the hot air under the bonnet. Coming up to christmas changed ecu,s back to standard so could run 95 octane. Due to could get for cheaper fuel through work to save money & purchased a HKS pod filter & cold air induction hose to mount pod filter outside of engine bay under guard.
After christmas fitted pod filter & refitted power fc took for drive found knock level out of control. Took to dyno to tune found engine leaning out badly had to raise fuel map severly to stop knocking on, 7 psi since then have fitted 255l/m walbro fuel pump & cleaned & flowed injectors found ok re dynoed still no good, checked fuel flow & pressure found really good.
After many many hours of wiring checks & self diagonistics check on standard ecu with no fault codes tried to run HKS pod filter with standard ecu still leaning out even when filter fitted in engine bay have changed with 3 different air flow meters still the same when crimp off return fuel line to richen up find ok since then refitted standard air box with k&n panel filter & checked afr found ok drives ok & does not lean out. However when idling & remove air filter instantly leans out put back in richens up pull back out leans out this is not right, should not matter if air filter is fitted or not. Since driving with standard air box fuel ratios dont stay consistent range from 14.5 to 11.6 on cruise would like to know if anyone would know how to fix this problem.