5GENSpecB

I have noticed it's slightly worse with the AC and headlights on and whatnot, but again, only once it's warm. With a bit of throttle and under more load its perfectly fine, it really does just appear to be an idling too low issue, but without it being a vacuum leak I'm a bit stuck as to what the root cause would be. I'll get vacuum leaks checked again, wondering if theres any plausibility behind leaky injectors?

Had a shop do the compression test for me so they pulled them out and looked at them for me then as part of that. Both those guys and another shop told me the plugs should still be fine, but yea will be replacing them soon anyway. Plus did think it would be a bit strange for the issue to only be happening in gear if it was the plugs but happy to be wrong there.

Hi all, Thought I'd post here to get a better gauge of the issue, got a 2014 Legacy Spec B (just under 80k kms) idling a bit low and causing a mild/moderate rough idle in gear only. When car is shifted to neutral or park it subsides entirely. Sometimes engine will idle fine causing rough idle to be almost unnoticeable, but revs will drop too low for just a moment causing a shudder and it picks itself back up. Other times it is just a bit low causing the rough idle at traffic lights and what not. Info about the car as follows: * Car has had compression test returning values of ~150psi for all 4 cylinders which is within normal range. * No vacuum leaks * MAF sensor cleaned * Throttle body cleaned * Spark plugs average condition, will be replacing soon as part of service regardless * Not throwing any codes * No warning lights * Cam belt replaced recently as due on the 10 year mark but issue preceded this replacement Saw a forum about AVCS solenoids (with a banjo bolt, couple of gaskets and a filter) causing a similar issue but not sure whether this was specific to the car being in gear and it appeared to be causing much more severe symptoms. Took mine to a shop recently and they said they didn't really notice the issue (which was difficult to believe) so they didn't end up investigating further. Any suggestions?