Toyota Repair Problems? Ask a Mechanic for Answers ASAP
How many miles do you have on this vehicle? Have you had any recent service work done or can you give me any history on the vehicle leading up to this problem?
The P0300 through P0306 are all for each one of the cylinder misfires. My main concern at this point would be for the P0354 which deals with the primary circuit of cylinder number 4 ignition coil. This should not affect the other cylinders misfiring however if there is any type of weird short or voltage surges it could potentially create problems with the other cylinders. Cylinder number four is the middle coil/cylinder if you are standing at the front bumper looking under the hood with the large plastic cover removed from the top of the engine. If you do not have any test equipment is difficult to definitively diagnose this. However to pay someone $100 or better to diagnose something is about the cost of one ignition coil. 90% of the time when you get a primary ignition coil malfunction code as you have with the P0354 code. This code normally sets when the computer does not see ignition coil confirmation or the IGF signal. The ignition coil for cylinder number 4 is relatively easy to change one electrical connector and 1 10 mm bolt hold it in place. You could swap it with another cylinder and this would confirm if the coil was bad because you would then get a primary ignition coil malfunction for the cylinder that you swap the two. If the check engine light is flashing you want to try and avoid to drive this vehicle as little as possible because you can cause catalytic converter damaged if the unburned fuel overheats the catalytic converter due to the misfire.