AFR's rich at idle all of a sudden (need some help)

[doridoridori]

So I have a SR Redtop, Sti yellow injectors (550s), Z32 maf, entalpy tune, S14 T28.

my maf went out a few weeks back, replaced it and my afr's were perfect at idle. Went to a drift event, car performed perfectly fine.
Then a few days after I noticed my AFR's were 10.7-11 at idle. Now at WOT they're perfect around 11.2WOT so no issues there but Im trying to figure out why it's rich at idle all of a sudden.

What could be causing this?

I have a AEM UEGO wideband, never had issues with it before and it isn't that old but any info/suggestions/help would be appreciated. Other than the numbers the car still drives perfectly fine

[Kingtal0n]

its usually a boost leak. a coupler is torn or something like that

perform a pressure test

Edit: just noticed you said WOT a/f was unchanged.
That means you might have a bad Narrowband O2,
simply unplug the narrowband and see if the problem vanishes.

Don't ever run the engine without the wideband turned "on" though. It says that in the instructions also

[jedi03]

can test by doing key on and see if wideband shows same numbers...if it does just need new 02 sensor for t

[doridoridori]

its usually a boost leak. a coupler is torn or something like that

perform a pressure test

Edit: just noticed you said WOT a/f was unchanged.
That means you might have a bad Narrowband O2,
simply unplug the narrowband and see if the problem vanishes.

Don't ever run the engine without the wideband turned "on" though. It says that in the instructions also

roger that i'll check that, appreciate the info!

[doridoridori]

can test by doing key on and see if wideband shows same numbers...if it does just need new 02 sensor for t

so just put the key to the "on" position and see if the wideband drops to the same rich number?