Need help diagnosing

Hello,

I recently took my 1999 3rd gen sr5 4runner to the mechanic after a flashing engine light came on. It happened after i drove 15 minutes with no problem, left the car sitting for 5 minutes and then it had a rough start and began shaking. A minute later the light starting flashing.
It periodically goes away after some driving (not always though) and the shaking persists.

I took it to the mechanics and they couldn’t find the issue. I eventually went to autozone and ran the code reader and found Cylinder 1 and 4 were misfiring as well as system too lean. I gave the mechanic that info and they diagnosed it needing new ignition coils and spark plugs (they tried to scam me on the MAF by charging me an hour for labor, took me 2 minutes to change it).

This solved the cylinder 4 misfire but not cylinder 1 (mechanic tried to tell me the car was fine…until i drove off and the light came back on as well as the shaking). They can’t seem to find the problem. There isn’t any evidence of coolant in the cylinder and the oil isnt milky or bubbly.

I think it might be either the vacuum leak, leak in the intake tube, or a leaky head gasket. But still the mechanics can’t find what’s wrong.
Gas this ever happened to you? Any specific tests we could run to diagnose the problems? How can i advise the mechanics to find the issue? They seem pretty done with the car and any suggestion i have they brush it off without putting much effort to look into it. Any ideas?

thank you for any help or advice

 

have you checked the lines going to and from the PCV valve?
and replace the PCV?

I was not throwing any codes, but had stumble on accelerating and sluggish throttle response...

hose to the PCV was rotten and PCV was clogged, under $20 fixed my problem

 

I get a vibration in the engine after she has sat for a week or so. Vibration has always cleared up after a few seconds.

Always was told that's an indication of a faulty\sticky fuel injector.

You may want to pull the plug on that misfiring cylinder and see if it tells a story.