I have a 2005 Evo 8 which i just bought. Two thousand miles ago the motor was completely rebuilt. Right now the car cruises just fine with normal AFR's but when boost rolls in the AFR's shoot down to 10.0 so I'm assuming it is even lower because that's as low as the gauge goes. Once the car is warm it tends to idle pretty bad as you can see fro the YouTube video. Attached I have a picture of the codes it is throwing as well as the engine bay. I threw in the engine bay pic because I feel like the MAF could have been damaged by the crappy filter. Any suggestions are appreciated as I am trying to bring this baby back to life. Thank you.

 

I would start with your MAF. The factory service manual has a good explanation about checking your temperature unit for "intake air temperature sensor check."

Also check the "volume air flow sensor check."
Corresponds to your P0102
• Volume airflow sensor failed.
• Open or shorted volume airflow sensor circuit,
harness damage or connector damage.
• ECM failed.

 

Man, that is a laundry list of codes bro. Do you have a logger?

 

I will have to find how to check the temperature unit online or something because they did not include a manual with the sale. I cleaned the MAF but go figure, it didn't fix anything. After I cleaned it I forgot to plug it in and it ran like absolute crap. Does that mean it is not the problem or could it still be just functioning poorly? I am currently out of town and will be back with the car on Thursday so that's when i can do some more diagnostics. Thanks for your help.

 

Yeah I'm not very happy about it. The guy who I bought it from told me only the 02 sensor was bad and that's the only code that went off. The car had no CEL when I bought it so I regretfully took his word for it. I guess this is what i get for not thoroughly looking at the car. I do not have a logger nor do i really know what that is/how it works because I'm quite new to this. I am interested in learning all of this so in the meantime ill do a little more research I guess.

 

Okay I just looked at your video. 2 things-- it looks like you are idling very rich but I don't think that's what the problem is. It sounds like something is resonating. I bet it's something that's not bolted tight. Sorry bro, I know there's a million bolts in the Evo but ......