Need a little help please rough idle sitting in driveway but fine at high speed

Hi there everyone, my tacoma has thrown several codes
P0300
P0304
P0306
P0456
0k first of all love my truck 2003 prerunner silver, but just recently it started idling rough, had it tuned up new plugs, wires, ignition coils. She ran like a champ here I am 5 days later and back to rough idle. My local mechanic wants to charge me again for another diagnostic test. Any ideas, I've also changed Evap canister, oxygen sensor. I'm at my wits end total miles is 213,000

 

Kinda sounds like a vacuum leak. If you have a code reader with live data, check fuel trim readings.

 

Have a code reader but I don't know how to do that.

 

Also the mechanic is telling me it's possibly the ECM

 

I just spent 2k getting my frame fixed

 

Does your rough idle include it going higher and lower? If so, consider cleaning your idler air control valve.

 

It runs smooth as a kitten on highway. I start it up it idles rough, put it in gear and it's worse. Get going at high speed and really good. It's weird. I'll try that and also clean my throttle body. What's your thoughts on the ECM

 

Going at highway speeds probably just masks the problem. What are the current codes that it's displaying now? Your mechanic seems to be just throwing parts at it without diagnosing anything. I'd take it somewhere else.

 

Find a new mechanic.

 

Seems unlikely. The ECM is not a typical wear item.

 

Agree with the folks above, not seeing how ECM is playing into this.

 

Agree with what everyone else is saying. Rule out smaller things before jumping to ECM. Also if your mechanic did this "tune-up", I'd check his work too. Or have the next guy check his work. He sounds kinda worthless tbh

 

Which engine?

 

It's 3.4 the mechanic is definitely out for money. It just makes no sense after total tuneup it ram great for a week then went right back to running bad again. It's almost like it's running on 2 cylinders. The timing belt was also replaced a year ago. A friend mentioned possibly the igniter that tells the coils to fire. Someone had asked for my codes p0300 p0304 p0306 looked them up all are cylinder misfire codes. I'm at a loss everything is new plugs, wires, ignition coils

 

Again double check all of his work. Could be a wide range of things to include [but not limited to]: coil packs, plug wires, plugs, MAF sensor, TPS sensor, PCV valve, vacuum leak. Double checking his work, then moving to vacuum line checks seems the most prudent first step though. Good chance this swindler used cheap non-OEM coils, wires, and plugs, and perhaps they failed way prematurely, or he didn't even torque plugs/coil packs properly, or something to that effect.

 

This. Valid point to run by your mech, did he use OEM parts in that tune up?

 

Just made appt with another mechanic. He mentioned spark plugs what kind were they? They were NkG plugs because I asked. The wires and coils came from autozone. He suggested running diagnostic test because this dude probably never did. He was more worried about screaming at my wife for clearing the code even though she wrote them all down. After he saw that the light was off he wasn't interested in even driving it to see what we were talking about.

 

Thanks for your posts cant get into new station until May 11th but I'll definitely update when I have some answers.

 

Sorry it all happened. Keep us updated OP

 

Here is an short introduction article on fuel trims along with a good video link.
https://www.thedrive.com/cars-101/38138/what-should-long-term-and-short-term-fuel-trim-be