Powertrain system too lean 😨
 

Hey guys, got an 03 wrx. Management fault is up saying "Powertrain-system too lean (bank 1)" .... can somebody advise me on what it actually is please. I know there's too much air going through the system, but can somebody tell me what bank 1 is? I had the secondary lambda probe replaced recently and a couple of hours after that this fault came up so i bought myself a code reader. could i find out what it is by using the torque pro app maybe?? bank 1 bank 1 bank 1 ........ damn my head and this car. i love it and spent far too much on her but i love her 😂

What's the actual error code that your logging?

PO171
 

Hey bro, its throwing up a PO171 fault. apparently it's fault common. iv looked into it, most are pointing to the MAF, I have an aftermarket HKS panel air filter on her but can't see that as a problem you think? i can check fuel trims and all that but have NO idea at what these are supposed to read and what my cars vital readings are supposed to be and idle and loaded. You think it's a good idea to clean the MAF first, clear the code, and see what happens??

Is the car standard and was the 02 sensor a genuine Denso part ?

Yes kinda
 

The car has all standard specifications, i do have a number of forged cosworth parts when i had my engine rebuild done. torque development did the build and the car has run fine with no faults for over a year. a few months ago a fault came up that lead exactly to the secondary lambda probe, that was rectified with a genuine part. The current fault flashed up within days after the new probe and when i went back for them to check the reader said it had "no data available" I see it with my own eyes. then a couple of weeks later i got my own readers and setups. its costing me a frickin bomb over the years for this car so im willing to learn all about it. i don't have any holes in my exaust and im sure the vacuuming isn't leaking. is there particular values or numbers that my MAF should be reading on idle or under load to determine it's that? what's the first thing you guys would do?

If its just the rear O2 sensor then have your mapper turn all the codes off for it. If you have a data logging cable then use romraider logger to "show ltv" data and post up the image it gives you.

cool
 

Ok mate, il get a screenshot of the layout. il be sure to upload in the next few days. thanks.

👍
 

thanks for the link bro, il check it out when i get home. think I'm gonna need expertise from you guys this time.

Sorry for the long update.
 

So I think iv diagnosed my problem hopefully. I few days ago i heard a strange hissing noise coming from the engine bay, it turns out that the T shaped hose connector from my boost gauge and vaccum pipe onto my air box/MAF had a split, I replaced the little hise and jubilee clipped it and it's been running fine for a few days no faults. also the idle was lumpy at the time i heard the hissing. thanks for the help boys. iv had trouble with my dedicated car laptop recently so had to reboot and install romraider again. looks a hard program to use, but no doubt very useful for datalogging. thanks again