02 wrx ej207

so I recently got a 02 wrx with a pre swapped ej207 it was lean at idle but I found the o2 sensor only had one good wire left so I replaced it with a denso one that fixed the idle but anything after 20-30% throttle it will peg lean on my aem eugo x series gauge I also tried a new maf and no change I’m waiting on a cable so I can start data logging and tune my car but any other ideas

I would check basics while waiting for cables. Make sure fuel pressure is good, fuel filter is not clogged. Stock intake? stock exhaust? ... Smoke test for leaks.. Does it have a cat?

Best of luck

It has a tomei inlet pipe a hks bov fully straight pipe no cat I’m also waiting on my buddy to get his smoke leak tester back so I can borrow that to test for leaves but I’m getting 19in/hg at idle and I have checked for leaks and so far couldn’t find any but I still have to check fuel pressure and I might just throw in a new fuel filter as well also has a stock airbox yet

your data logging will show you if you have fuel trims that may be hindering it but as above start with basics injector cleaning flow test etc

Thank you I’m going to try a fuel filter today and see if that was clogged and I’ll get my cable in tomorrow so I can start logging and see if their is anything wrong with fuel trims but it seems to only happen when it goes into a open loop

Update no luck with just the fuel filter but I scanned my car at oriellys and the map sensor reads 10kpa at idle idk if that’s normal or not

Hi Brady,

All of the Subaru' that i have worked on have idled at around 40kPa ~ 50 kPa, 10 kPa is seen in overrun conditions but not idle. What does the sensor read when the engine is off?