Mazdaspeed 3 Lean AFR @ Idle

Greg Senge

Greg Senge

Greenie N00B Member
Hello ya'll. I'm new to this forum but I figured this might be a good place to start with troubleshooting my issue. I just put a BNR S4 and all the goodies I needed. I've been self tuning on ATR and I cant seem to fix my idle, It'll hold 14.7 but will bounce to 15 and maybe 16 AFR. I've checked everywhere for vacuum leaks, exhaust leaks, and I checked my fueling in the tune and all seems to be fine. Attached is the file, LMK if you have suggestions. TIA
 

Attachments

Awafrican said:
Have you done a maf calibration yet? https://www.mazdaspeeds.org/index.php?threads/mafcals-for-bigger-intakes.10280/
Click to expand...

If it were a MAF cal issue, his fuel trims would stay consistently bad. His fuel trims are bouncing around within acceptable levels. Please read his log for this information.

It seems like your ECU is trying to compensate for something. Is this log taken at operating coolant temp?

Did you install a new or used BNR S4? Did you install any other supporting mods (like a MAP sensor)?

Installing a turbo requires quite a few parts removed. Did you reuse any gaskets? Did you replace with OEM gaskets?
 
Lean at idle is usually a vacuum leak. Can you try capping off the Purge Solenoid port at the intake manifold to see if the fuel trims correct themselves?
 
The_big_dill said:
If it were a MAF cal issue, his fuel trims would stay consistently bad. His fuel trims are bouncing around within acceptable levels. Please read his log for this information.

It seems like your ECU is trying to compensate for something. Is this log taken at operating coolant temp?

Did you install a new or used BNR S4? Did you install any other supporting mods (like a MAP sensor)?

Installing a turbo requires quite a few parts removed. Did you reuse any gaskets? Did you replace with OEM gaskets?
Click to expand...
I bought the Bnr used, but all my gaskets and hardware was new. I put a 3.5 bar map in, 3.5 intake, 3 port ebcs, and 3”catless downpipe on when I did the s4. Everything in my signature other than those have been on for about a year. It seems to be fixing itself. Knock on wood...
 
L337TurboZ said:
Lean at idle is usually a vacuum leak. Can you try capping off the Purge Solenoid port at the intake manifold to see if the fuel trims correct themselves?
Click to expand...
I checked everything vaccum and boost pipes related except the purge solenoid... I can give it a shot
 
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