CCorey

Have the following codes P300 P301 P303 P305. Ignition Coils and Spark plugs have been replaced.

Check Engine light blinks and will go solid, Trac Off comes on. Brakes have intermittent softness.

Any ideas ? Would think it has to do with Bank 1

ES300NZ

http://engine-codes.com/p0300_toyota.html
The P0300 code means that a cylinder(s) is misfiring or is randomly misfiring. Start by checking for intake leaks, intake gaskets are common caused of multi-cylinder misfiring. If no leak are found the next step is to replace the spark plugs. If the problem persist more tests needs to be done to diagnose problem, see "Possible Causes"

The P0301 code means that the cylinder 1 is misfiring or is randomly misfiring. Start by checking for intake leaks an if no leaks are found the next step is to replace the spark plugs on cylinder 1. If the problem persist more tests needs to be done to diagnose problem, see "Possible Causes"

Read more: http://engine-codes.com/p0301_toyota.html#ixzz3gZGh3Mmx

The P0303 code means that the cylinder 3 is misfiring or is randomly misfiring. Start by checking for intake leaks an if no leaks are found the next step is to replace the spark plugs on cylinder 3. If the problem persist more tests needs to be done to diagnose problem, see "Possible Causes"

Read more: http://engine-codes.com/p0303_toyota.html#ixzz3gZH3xsCe

The P0305 code means that the cylinder 5 is misfiring or is randomly misfiring. Start by checking for intake leaks an if no leaks are found the next step is to replace the spark plugs on cylinder 5. If the problem persist more tests needs to be done to diagnose problem, see "Possible Causes"

Read more: http://engine-codes.com/p0305_toyota.html#ixzz3gZHA9xUj

So, an entire bank is misfiring, and there could be alot of causes for that, probably too many to list. Start by checking the harness for damage, the earth connection. Remove the fuel rails, blow them out with air, replace the o-rings(good practise) with viton ones (for ethanol based fuels). The rest is diagnosis stuff, it probably won't be the fuel pump since it's only one bank. It's likely a electrical issue, or a timing issue. It could be the VVTI solenoids, if you have that.

DRACO A5OG

Check your Fuel Pressure Regulator and check the ohms on the fuel injectors.

When I had these codes it was due to a leaking Fuel Pressure Regulator, swapped, codes gone.

Recently I have been having a rich running condition, checked resistance on the fuel injectors, should be 13.4-14.3 but it read 16.1-16.2. time to swap :-/

ES300NZ

interesting, .. I learning from this posting. (seriously).

amlarajr01

To help you out I can almost definitely tell you its not a spark plug or ignition coil problem. Its all on one side like they said. Pointing to either a fuel or air issue. Do you have the tools required to check fuel pressure on that one side or a friend with the tool to pull live codes from ecu> The ecu will tell you if your running rich or lean on that side. Good place to start. If your running lean and have adequate pressure at the rail on that side then you are more than likely have a vacuum leak on that side. It wont be fuel injector or a spark plugs or coil due to its all three on one side. Chances off all three missing like that are a million to one. If you have any more questions feel free to ask

tomf

Check your VVTI solenoids, also know as oil control valves (OCV) and OCV filters. A bad OCV can cause your symptoms. However I'd expect an OCV error. But it's worth as shot because it's easy.