I have a problem with my idle on my 2008 Evo X. During idle, my wideband shows that my AFR would go lean (17+). It would then go back to around 14.7 again after a few seconds, and it repeats this cycle. I'm suspecting that it could be my MAF sensor, because I double checked all my vacuum hoses, intake, and bov.

Would there be anyone around the GVA or Richmond, BC that could take a look at my idle issue.

Thanks in advance!

 

What tune are you running and what mods?

 

At this moment, I'm getting E-tuned.
All I have right now is an intake, turboback exhaust, and a 3 port.

 

I'm actually thinking that the problem might be that my brake booster has a vacuum leak because there might not be an O-ring.

 

hmm, it could be a lot of things. I'd check for that vacuum leak first. Other than that it could be many things tune related or mechanical. could be the injectors, maf scaling, fuel relay, etc.

 

I'm using the new relays from SSP, and the maf scaling should be correct from my E-tuner. Hopefully its just the vacuum leak between the brake booster and master cylinder.

Thanks for your help though!

 

Just a little update, it was indeed the O-ring between the brake booster and master cylinder. I put some silicon between them, and my idle is much more stable, and my brakes are much firmer too!

 

glad you got it sorted out!