Bad MAF sensor?

Juandiegohf

Greenie N00B Member
Hey everyone, I’m pretty new to the mps and overall modding community so please don’t hate on me too much hahaha!

I’ve recently purchased an 06 Mazda6 mps and it has 146000kms on the clock. Ever since I’ve bought it I’ve been noticing (and got told) the car has been running rich. I’m trying to pin point to the problem and solve it asap. the mechanic that helped me out pick out the car said it probably had to do with a poor tune. But after inspecting it I realised the car has a PD therefore I doubt that be the cause. However I will get a touch up tune since I’m not sure if any mods have been done since it was tuned. (I doubt it tough)

I did some basics already; I got a fuel additive toaybe try and clean up a bit the fuel lines and injectors to see if it helped but little has changed. Then decided to clean up the TB and MAF sensor which I thought might help the cold starts since it wasn’t idling smoothly; plus after reving the engine the rpm’s tends to “chase” for a bit before the come back down to idle (this does it all the time)

AFR tends to be at 14.7 and drops to 14.55 intermittently whilst it idles

Today I started my car in the morning and the idle was worse than prior to the clean down. After that I decided to unplug the MAF sensor to see if maybe if the car would stall or not (which didn’t) after plugging it back my STFT and HTFT went to shits (STFT hit -20/20 and LTFT -18.8/-0.16 or so whilst driving back home)

Now my question is, does this mean the MAF sensor is the faulty one or did I just cause it by unplugging it and now need to get my MAF recalibrated?

Also, there’s this very strange engine hunt or rev up when I try to shift from 5th or 6th gear (it does it either with load or just cruising). It tends to rev up maybe 300/500 rpms once I press the clutch. Could the MAF be causing all this issues?

Thanks in advance!!
 

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Welcome to mso!

Have you conducted a boost leak test? What's are ltft at idle and cruise

Thank you!

So, last night I actually took it out for a spin to see my MAF readings and both my gs and voltage seemed alright but then realised I wasn’t hitting target psi, to what I assumed I had some sort of boost leak; within a few pulls one of my intercooler pipes came off lol. I assume I must’ve left it a bit loose after cleaning the TB. However I don’t know if it’s just me but but those clamps provided for the HiD fmic seem a bit like the might come off any time soon. I added an extra clamp on top and took it out again. I was hitting target boost and my ltft was a bit better -15.4 when cruising and around -4 on idle. Stft do still hit really high numbers both ways -/+ but I’m not too sure how they looked like before; at idle they seemed to stay around -3/3 or so, more towards the +

before cleaning the parts I was roughly around -10 whilst cursing and -5 at idle.

I will however conduct a boost leak since I’ve heard this could also be one of the reasons why I might be running rich?

Thanks!
 

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That 10 on ltft is out of spec you've got a leak and yes it'll cause lean / rich issues trying to compensate. Below is the breakdown of where you want ltft to be
Pre-turbo = + trims, air added or sucked in
turbo to TP = - trims, air lost or pushed out
post TP = + trims, air added or sucked in

+5 or -5 is ideal
+7 or - 7 not crazy might want to look into it
+10 or -10 look into it , you got a leak
+20 or -20 shits broke yo
 
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