running rich, codes and exhaust soot

[jpr 3]

My Cup V6 is running rich according to the engine codes that I have retrieved with the code reader.  the engine is rich on both banks so I'm getting both 172 and 175 codes.  I can see some black soot residue on the back of the car and notice that, when revving the engine with the car at a standstill, upon tip in the throttle (with healthy throttle application), I can see the trace of black smoke in the exhaust, especially, from low rpm.  The code reader shows me that the engine ecu is trying to trim down the mixture at idle but its not able to get it to where it wants.  That leads me to believe that the oxigen sensors are good (telling the ecu that it needs to cut fuel) but something else (suspect the MAF sensor) is holding it back.  I clear the codes and they come back after a while.  Any input is appreciated!

Thanks

Jpr

[Kristof Thys 189]

Would try cleaning/replacing the MAF as a first step.  Second step, clean aircleaner/airfilter.  Do you have the HKS green "sponge" filter... can be clogged up (or is this V6 CupR only?)

 

As per the workbook, some other culprits might exist:

 

Fuel    pressure    too    high •    

Leaking    fuel    injector • 

Restriction    in    the    exhaust    system    or    air    intake    /    filter • 

Erratic    throttle    position    sensor • 

MAF    fault • 

O2    sensor    fault • 

Ignition    fault

Edited December 23, 2019 by Kristof Thys

[jpr 3]

Thanks Kristof,

Yeah, the filter was very dirty. Replaced it with a new BMC foam type (it was the original one as well).  Will try to clean the MAF and see how it goes.

Thanks

[Kristof Thys 189]

9 hours ago, jpr said:

Thanks Kristof,

Yeah, the filter was very dirty. Replaced it with a new BMC foam type (it was the original one as well).  Will try to clean the MAF and see how it goes.

Thanks

look into the throttle body too as the flap might not fully close due to pcv dumping oil + some dirt gone through the airfilter; clean out.