shane_evo7

hey all,

Just recently my evo has been having a weird idle/ AFR issue,

at idle the AFR jumps from 10 to 17 and anywhere in between and it is very rough,

the car runs fine when highway cruising and when going WOT the afr is good,

if i do a little pull the slow down and push the clutch in the car tries to stall out and bogs

I recently installed a kill switch on the fuel pump relay and i thought that it could be the issue but i removed it and rewired it like normal and it still has the issue,

However when i Turn the AC on the idle is fine and the AFR is perfect at idle and it doesn't try to stall or bog after pulls.

Also cleaned the maf, still has issue

Also installed a new LICP ut checked that and it looks good and secure,

I also have had a louder turbo noise/whine after installing a new downpipe, not sure if its just normal for a aftermarket downpipe or what but I have had that noise for a while and had never had a issue.

Any ideas on what it could be? Boost leak? bad maf? bad sensor?

any help is appreciated

ghost911

have you figured out what it was? Since no one on here help you.

Apex Hunter

iTrader: (1)

Based off your UN, i'm guessing you have an Evo 7?

Not sure if this holds true for the 7, but on the USDM 8 I believe (please correct me if i'm wrong) the primary job of the factory MAP sensor is to help with fuel metering at very low load, like idle. Once you transition into higher load conditions, the MAF takes over fuel metering duties.

I might try troubleshooting the MAP sensor to make sure it's functioning properly.