Engine random misfire when AC is on

Hi guys. I got an issue with my gen3 2016 Tacoma. Love the truck but have a serious problem. Last week my truck started misfiring randomly and the check engine light comes on and I lose power. I pull over and turn it off and turn it on again and the problem is gone temporarily. I found that this only happens when I have the A/C on. If it starts misfiring and I turn the AC off, the problem goes away. I took it to a dealership (possibly a bad idea) and they said that cylinder #1 was misfiring. They changed all my plugs and cleaned my fuel injectors. Driving the next day problem still there. Yikes. I don’t want them to charge me another $700 for work that doesn’t get to the root of the problem. Any ideas on what the issue might be? Thanks.

 

There have been posts here of burnt valves on #1 IIRC.

 

Take it back and ask for the 700.00 back,or fix my truck. Simple. They cant charge you all that to just shotgun some parts.

 

This.

 

This, you paid them to fix it,,, so fix it. If nothing else, a good dealer will apply a credit towards actual fix.
I can cartpetbomb at home and save money, I wouldn't expect to pay a shop to do the same.

 

Mechanics are kind of like doctors; sometimes they have to take their best guess on what is causing an issue. Most times they get it right, but sometimes they do not! Hopefully they will work with you.

 

Changing the plugs and cleaning the fuel injectors seems like a pretty piss-poor diagnosis for a single-cylinder misfire. I would start by swapping the coil pack with another just to rule that out (very unlikely, but possible), then assuming that doesn't do the trick, you're going to need a good quality scan tool with a lot of live data PIDs so that you can compare parameters between the affected and a non-affected cylinder. Almost certainly there will be a clue in there.

 

They're kind of like that. But they shouldn't be. There's almost no instance where something can't be verified to prove 100% that part X or wire B is definitely causing the issue.

 

Update:
Thank you all for your Tacoma therapy.
The dealership took my Tacoma back and swapped the #1 and #5 coils and the computer came back reporting that #5 was now misfiring. Bad coil. They think the plug went bad and that caused the coil to have problems.
So they ate the labor but charged for the coil. ($115)
Problem solved. Thx again guys.

 

Nice.. gotta admit, I didn't really think it was a coil, but glad they figured it out.

 

Glad you didn't have the valve issue others have had.

I'm not sure I buy a 'plug going bad' doing the coil in, but whatever. It's fixed.

Most of all thanks for letting us know the resolution. So many ask for help then wander off w/o letting the group know what happened.

 

$815 to swap a coil is strong.