2nd opinion on vibration while at low RPMs

I have a 2006 tacoma TRD offroad w/ ~ 233k miles on it. Recently I noticed that there is a fluttering vibration when I am parked and when I am at a red light (fully stopped). The RPMs sit at ~600 but every few seconds the RPMs dip to 500 and that vibration is felt.

I have a feeling that it has something to do with either vacuum leak or MAF.

I do not have any issues when accelerating or at any speed other than when parked or while braked (at a stop light)- to clarify it doesnt happen when I am slowing down either, only after a few seconds after coming to a complete stop. There is not a check engine light on either. Everything is stock engine related as well.

Any input is greatly appreciated, I am on the road not at my usual shop or else I would tear everything down to troubleshoot the issue.

 

Have you properly cleaned the MFA
When last time air filter was changed
Have you checked trans fluid to see if full
Just throwing stuff out there
Many people on here more
Experienced

 

I am waiting on a throttle body gasket to come in the mail, so that I can replace it after I dis-assemble the throttle body for cleaning I can replace it in one swoop. I am going to also clean out the mass air flow sensor while I am at it (lets hope that dont break....). Air filter is clean, visual inspections look good. I recently changed out my trans fluid ~7,500 miles ago and the fluid level is still good. I also suspect maybe the integrated IAB on the throttle body could be giving me some issues since the problem is only on idle; I am going to look closer at that when I clean the throttle body. Over the past few days the rough idle has worsened/ increased in frequency.

 

They make MAF sensor cleaning spray

 

Any codes ?
This is a completely computerized truck . No check engine light doesnt mean there are no codes .
When was last spark plugs ? Primary and secondary ignition could be looked at .
Fuel pressure as well as valve timing , O2 sensors, fuel trim all come into play

 

That is a good point. I will plug in my OBD2 scanner (BLUEDRIVER for the win)- IDK why i havnt already done that....shoulda known there would still be codes. The last time I changed my spark plugs was at ~170k miles. So 232k-170k= 62k miles....I have neglected my baby......I will change theme out too while I am under the hood.