Code P0301

Anyone help me out? Threw a code on the way home from work. Scan gauge says P0301. Anyone got a code book? Thanks

 

Missfire detected cylinder 1.
http://www.toyotanation.com/forum/showthread.php?t=148676

 

thanks man. Guess i better check my spark plugs and my o2 sensor since i think those would be the cause of the problem most likely right?

 

if you figure it out let me know!

 

Plug, wire, or coil. Good places to begin.

 

ya i googled it and it said the plug coil or wire. it also said their should be some hard starting or rough idle so i might clear the code and see if it pops up again cus i have neither of those happening

 

What you can also do is run some "injector clean" through to clean the injectors. A cylinder misfire is usually your injector getting plugged. Clean them up and see how she idles. If it doesnt work, look into getting your injectors serviced

 

start with spark, then fuel(so u dont blow urself up checking spark after u cracked open a fuel line LOL) then compression.

 

thanks guys. ill definitely run some injector cleaner first since thats simple and easiest right now cus with school and work i dont have the time to pull the injectors

 

okay cleared the code. now a P0125 and a P1135 are coming up

 

What does your temp gauge show? Needle should be around 1/2 of the sweep, pointing at 9 o'clock approximately.

 

yup always there ive never seen it go hgher than half

 

P0125 - Insufficient Coolant Temperature for Closed Loop Fuel Control

* Not sure about this one...

P1135 - Air/Fuel Sensor Heater Circuit Response. (Bank 1 Sensor 1)

Most likely your pre-cat 02 sensor

 

ya thats what my mechanic buddy said about 1135 but he wasnt sure about the 0125 either

 

Ive been having the problem of the P0125 for a little while ive done everything its come down to see that its my Front Oxygen Sensor. Most likey this is the case all the time for this code anyways.

 

Just had the same issues, with the same codes last weekend.

Went through all the tests, just to find a bad plug wire. The second two codes pop up because the raw fuel is passing through the combustion chamber unburned. The #1 cylinder isn't firing all the time, so it creates an ultra rich condition flagging the codes.

If you have a meter, check your wires. None of them should read higher than 25K Ohms of resistance.

I had #1 wire with 78K ohms. Started misfiring under load, but idled perfectly and started easily.

I changed my plugs and wires to OE NGK's and cleared the codes. She runs like new!!

Good Luck!

 

idle is now rough and start up is hard on cold mornings so i think its the spark plugs. i just need a weekend off to fix it

 

got spark plugs changed out. still throwing p0125 and p1130, so guessin it is my o2 sensor. how hard is it to replace and where can i find it. thanks guys

 

I'd say that if spark plugs weren't within your scope, the O2 sensor isn't a project you'd want to tackle. Shop time again?