P0301 code

snowninja

New member
went skiing this weekend and on the way up to the mountain the CEL started flashing then went steady on and off a couple times. I could feel a little shudder/stutter at lower RPM's but then I would throttle up and everything felt fine. same thing on the way home. today I took it to autozone to borrow the scanner and it stored 300 and 301 codes. 300 is general and 301 is misfire on cylinder 1. 4 options, injector, coil pack, plugs, wires. plugs and wires are a year old done at dealer. would think that if coil pack was bad 1 and 3 cylinders would misfire but maybe not? dealer wants $250 to replace #1 injector. How hard is this to do having never done it, I am pretty handy and have basic tools. I priced 2 different injectors from parts stores and both were around $100 so i'd be out about $150 to have the dealer do it. having never done this before would it take me more than a couple hours to do and what could I screw up along the way? I have a Chiltons and also access to a FSM.

funny thing is i got a can of carb cleaner put it in and drove it 10 miles home, no sputter or shudder or stutter.. AT ALL.. could that really have fixed it or just coincidence? i am going to take it on another hilly test drive right now..
 
Register to hide this ad
don't jump to injectors, thats too expensive.

Cheap things First. Plugs, Wires(i know there not that old, but still cheaper then doing an unnecessary injector) and swap a coil pack to another cylinder. Then see what happens, and report back.

edit: also make sure you have dual ground plugs, although if the dealer did them they should know that.
 
Last edited:
don't jump to injectors, thats too expensive.

Cheap things First. Plugs, Wires(i know there not that old, but still cheaper then doing an unnecessary injector) and swap a coil pack to another cylinder. Then see what happens, and report back.

edit: also make sure you have dual ground plugs, although if the dealer did them they should know that.

ok will try this and report back, thanks
 
I have been pricing parts and none of the aftermarket parts stores have the dual ground NGK plugs, Toyota dealer has them (denso) for $6/each. I found a wire kit (wires and boots) at napa for $75 and Toyota has the kit for $83. so dealership total of $125 for all plugs, wires, boots. Is there a better place to get these or is the dealer the best option? They also have everything in stock so no need to order, wait, etc..
 
if you have a multimeter, you can check the resistance on the plug wires, injectors, and coils to see if they're in spec. better than throwing money at the problem hoping to fix it.
 
VJ whisperer has a good point (and hilarious username--that im kind of suprised was allowed)

If you have a multimeter you can check to see if coil, wires, and injectors are in the specified range, but I have heard/seen/read about both injectors and coil packs that tested in range and were still found to be the culprit. It's still worth it to check if you have the capability but is not 100% conclusive.

You could save about ten bucks on plugs, and (working on memory) about thirty bucks on wires if you can deal with the misfire while you order the parts you need from amazon. (thats NGK wires not OEM) In the meantime you could still move the coil pack for cylinder 1 to another cylinder and see if the misfire follows it.

It's kind of up to you though. You can almost always save money by buying from somewhere other then the dealer and doing the work yourself. For just plugs and wires(and switching a coil pack around) it looks like you could save about 50 bucks by not letting the dealer do it.

From the OP, it doesn't sound like the misfire is that bad. So, In my opinion I would order the parts and save some money. The misfire shouldn't hurt anything in the few days it would take for the parts to come in.

edit: try the free thing first, switch a coil pack you may not need plugs or wires
 
Last edited:
ok thanks guys, i'll look into the other places to save some money if I can. i do have an ohm meter and can test these things but i'll tell you that i bought a can of berrymans b12 injector cleaner put it in, have driven 20 miles now and the CEL light went off and it's driving totally normal (for) now. is it really possible that this has fixed the problem?? is it at all likely?? don't get me wrong i'll still test the parts but if i only had to spend $5 on some injector cleaner that will be the best Christmas present to old whitey - after all he has 278k miles on him..
 
yeah, sure it's possible. I hope it takes care of it. If it does solve it then you may have had an injector issue after all. Maybe you had one that was ever so slightly clogged. If it does go away maybe pick up another can in a week or so and run it through again, make sure you got it all.

Hope you're back on the road for good. Oh and Welcome to the forum.
 
thanks for the welcome HC. my wife offered to test it some more on her drive to work (about 40 miles roundtrip) today so if it holds, i'll chalk it up to dirty injector but I'm skeptical to say the least. will report back any changes and thanks all for the quick response!!

happy travels
 
Its back. This is my daily driver so I decided to take it in. They swapped wires plugs and coil packs and the problem didn't follow any so it points to injector.. $250 to replace it failed tests. Recommend cleaning the other 5 which they send out to a shop to do. Claim they come back like brand new. $400 to do this. Water pump leaking I have never replaced timing belt. $675 to do this.. why do I feel like I'm getting raped..
 
Forgo getting the injectors professionally clean unless you have the deep wallet for it.

$675 is cheap for the timing belt/H20 pump, at least for around here in DC/VA metro, where the cost is 2 1/2 times your quoted amount. But it needs to be done.
 
Its back. This is my daily driver so I decided to take it in. They swapped wires plugs and coil packs and the problem didn't follow any so it points to injector.. $250 to replace it failed tests. Recommend cleaning the other 5 which they send out to a shop to do. Claim they come back like brand new. $400 to do this. Water pump leaking I have never replaced timing belt. $675 to do this.. why do I feel like I'm getting raped..

Does it use any water whatsoever? I had a P303, cylinder 3 misfire that would come and go with no visible white smoke, but it did use a small amount of water. I did plugs, coil pack, injector and it would always return. Eventually at 227K the problem came and never went away. I had a cracked head. Hopefully that's not the case, but with 278K I wouldn't rule it out.

You can get a full set of OE re-man injectors off Ebay for around $120. I've gotten one and it looked new and worked great.

Click Here!!!!!!!!!!!
 
Last edited:
I didn't notice leaks but they said the coolant res was low.I hope not a bigger issue.. I opted not to do the other injectors and plan to buy a set and if another one goes I'll replace all of them.
 
Injector swap isn't tough, you could do it in about an hour in your driveway.

I would actually recommend you pull all of them, send them to WitchHunter.com (which is in your area) and get the OEM injectors cleaned/rebuilt. Aftermarket injectors are garbage.

However, before going that route, pull the plugs and give it a compression and/or leak down test. You mentioned 4 possible causes, but you forgot number 5: compression. And with 278K miles, it's quite possible you may have a compression issue. Hope not, but it's possible.
 
Injector swap isn't tough, you could do it in about an hour in your driveway.

I would actually recommend you pull all of them, send them to WitchHunter.com (which is in your area) and get the OEM injectors cleaned/rebuilt. Aftermarket injectors are garbage.

However, before going that route, pull the plugs and give it a compression and/or leak down test. You mentioned 4 possible causes, but you forgot number 5: compression. And with 278K miles, it's quite possible you may have a compression issue. Hope not, but it's possible.

Well its in the shop now. I'll ask them to give me the old injector. Thanks for the witchhunter tip I actually drive thru Duvall every day so would save me the shipping costs!! I can do a compression test I do have a gauge. Will do that this weekend. Once I get it back, what else should I check/replace? Admittedly I have not been very good to this rig, I need to start paying it forward if not too late.. Last year the O2 sensor, fuel filter, valve cover gaskets, and pcv were done.. Also at this mileage should I change the oil more frequently than 5k miles? What about my drive fluids? Transmission, diffs, etc? Been 100 k since any of them were done..

Thanks guys.
 

Members online

Forum statistics

Threads
278,304
Messages
3,554,041
Members
248,016
Latest member
Advally Service

Trending content

Back
Top