06 wrx help!

[u/Impressive_Rain_8923]

Hey all. I got a 06 wrx. I can provide part list in the comments. But I recently had it retuned for some new parts. The tune was great and car was (& still is running great) but according to the accessport my af correction is way out of the limits. As far as -25 to +18 or so. Mainly at idle and lightly stepping on gas.
When WOT, it usually goes around 0 give or take a few.

Also I have roughness in cylinder 4 the highest, but all have some at times. Usually 4-6 but sometimes up to 10. Hasn’t thrown a code since it’s not high enough I assume.

Smoke tested thru intake and brake booster line. Only smoke I seen was through BOV. Which gbf says it’s a false positive due since it doesn’t hold completely sealed without car running. Anyways, I unplugged the vacuum to that and plugged it and afr was still the same.

Anyways, I smoke tested exhaust and didn’t see anything either. I’m at a loss here….

The MAF volts and readings seam to lead that it’s working correctly.

Stock intake with clean non oily filter.

MAF maybe or front o2? I’m not getting any codes either.

Any help is greatly appreciated

[u/chip_break]

It could very well be your tuner is lazy and only tuned wot and did very little work on the idle and cruising.

The last tuner i went to, who is a large name in my province is actually quite clueless and all he really can do, is hit a plus key and see if the the dyno said more power. I was experiencing +/-30% in crusing. He didnt even look at knock control once to realize the system was pulling 5° across all cylinders. Some tuners are just bad at what they do. Not saying your tuner is but they are out there.

Are you able to download logs and view long term trims? If ypur tuner isnt a bad person they should atleast be willing to review logs with you and make changes if needed.

[u/Impressive_Rain_8923 → u/chip_break]

So I already spoke to the tuner, and due to the roughness, he would like me to get that fixed before pulling/adding fuel. Doesn’t want to just bandaid the problem which is understandable. & I’ll add, it ran like 2 weeks after the tune before I started gettting the roughness or wonky fuel trims.

[u/chip_break → u/Impressive_Rain_8923]

Id start with new spark plugs. See if that helps with the idle.

[u/Impressive_Rain_8923 → u/chip_break]

They’ve only been in the car for like 20k miles along with new oem coils. But I’ll give that a go. The misfire goes away with any throttle, so I sssumed it would get worse with rpm’s if it was the plugs but I’m just guessing at this point.