Check engine light help

I have a 2001 Tacoma with the 3.4 v6. The following codes my reader are pulling is a p0300 p0301 and p0304. I've changed the spark plugs, made sure the Coils are firing right. Also the timing belt is good and in time. Fuel filter has been changed. Has compression. Also taken it and had a fuel injection cleaning done. The maf sensor is good also cleaned. Any help would be appreciated.

 

you are getting misfire codes so replace all spark plug wires and replace the coils that are giving you the codes. switch the coils to a different spark plug location first, just to confirm that the CEL code also switches to the other cylinder so you know that coil is bad. otherwise its going to be an electrical issue not telling the coil to fire.

 

I've replaced the spark plug wires and coils.

 

Misfire on cylider# 1 and 4, the #1 coil provides spark for both of those cylinders, swap the #1 coil with one of the other ones like keakar said and see if the misfire moves with it. if it does the coil is bad, if not start looking into what triggers the coil, ie igniter or ecm

 

Thanks for the replys I've tried swapping the coils even having bran new toyota coils and the misfires don't move. I've never seen the igniter/ ignition control module hit and miss they just totally quit working so maybe it is the ecm. I'm gonna bite the bullet and take it toyota I guess my brain is racked. Thanks for the help.

 

not a bad move at this point, it sounds like you have something more then a "routine" problem going on. after the diagnose it I hope its not the ECM, if it is, you can change that yourself and you can find used ones sold for a couple hundred dollars so don't go buying a new one for $1500 from the dealer unless you insist on brand new.

 

Went through a similar chain of events a year ago. Is the truck running 'rough' on initial (cold) startup? Evening out as operating temp approaches?

We had a cracked cylinder head. Coolant would 'pool' in the combustion chamber while cold. The cylinder wouldn't fire on startup (P0304 - missfire #4). Crack would seal when warm.

I blamed mine on a heli-coil insert for the plug...

 

No the truck runs fine. It's only jerked one time while driving and cut off.

 

I bit the bullet and took it to Toyota within 2 hours I get a call back. They told me the number one injector is bad. That's sad a mechanic of 30+ years couldn't figure it out. He even lied about swapping that injector to cylinder three and that's not possible without removing the intake and splitting the fuel rail. I'm gonna have them adjust the valves while they have it tore down.

 

interesting with the 2 misfire codes, did they both come back after you did the plugs wires and coils?

 

Yes they both came back after putting new plugs plus wires and coils.