Can I get away without Toyota parts for plugs, injectors, or coils?

Have you cleaned the throttle body?

 

I've almost never noticed a difference buying the cheapest possible parts online. Though NGK spark plugs I don't skimp on. What's more, Toyota has lots of standard parts across models... For example the plugs and fuel injectors work on lots of different Toyota models and aftermarket ones aren't problematic.

But more to the point, swapping out parts without doing a thorough diagnosis is usually the most expensive way to fix something.

Any additional symptoms? How's the MPG? Any warning lights or error codes?

If it were my job I'd be looking for an error code for throttle body position sensor and if confirmed swapping the throttle body out with one from the wrecking yard so you aren't spending too much money.

 

On the spark plugs don't skimp get the real deal they're not that expensive they generally go a hundred thousand miles a little more if you want to push it for coils and things like that try the TRQ brand on Amazon or eBay I've had very good luck with them I'm running some of their stuff now near 100,000 miles with no problems no replacements no warranty replacements nothing just solid running hub bearings and coils they seem to do a good job with them no problem set a coils was like $89 for all four of them tire pressure monitor sensors bought a set for $24.99 look like copies of the original Pacific branded or their original pacifics there's nothing to them so they shouldn't be $40 a tire or a wheel 30 bucks for a set actually sounds reasonable and they all work fine haven't had any real problems

 

Amazon and eBay are extremely risky for autoparts: tons of counterfeits and zero accountability. It is possible to get quality parts out of Amazon, but very difficult to be certain you've got something that isn't garbage that can hurt you or your car.

Rockauto.com has been a happy medium for me. Cheaper than the Toyota parts window and good quality stuff if you avoid the 'economy' category.

Now some specifics? Rock has Denso and NGK plugs, genuine ones, and they have good prices.

For coils? A Prius is pretty good about catching and logging a coil problem with a specific code, so think twice before firing that parts cannon.

Lastly for fuel injectors consider a rebuild service. There are some small companies out there that will take your injectors and rebuild them and do a proper flow test on the bench, and this is very economical compared to buying quality replacements. Some can even do an advanced exchange so you aren't down as long.

Good luck!

 

IMHO; get a proper diagnoses rather than just aiming a parts cannon at your car. Installing questionable parts can mask/exacerbate and create other issues that'll take you off the correct path to properly repairing you car.

Just my 2-cents..

Seem to be a head gasket seepage issue. Do a compression and leak-down test when cold and another one when engine is hot. There shouldn't be much of a difference in the two test results. If there is, more than likely, heat expansion of the motor is sealing the head gasket leak, ergo misfires resolving themselves when hot.

 

Do a borescope test - don’t throw away money on parts you don’t need - or worse, on parts that give you two problems instead of one.

Car Care Nut HG Borescope at 7:40

 

Do the plugs first. You're almost exactly due for them, and an old set can cause ignition misfires, and your symptom description lines up well with that.

If that work alone doesn't yield satisfactory results I would proceed with injector rebuild service.

I would hold off on doing coils until you have clear diagnostic indications. It's almost $200 for a set worth installing, so it's not something most people do "just because they're in there."


Edit: adding: RJparker raises a good point about checking for a blown head gasket. You can do this while replacing the spark plugs, if you have a good borescope tool.

The model of engine you have doesn't seem to have many problems with its head gaskets... but after 330k miles anything's fair, right? Definitely worth checking.

 

Not if you want it to ever work again

 

Sure! But why would you want to????
If your son is doing all of the labour why not stick the crowbar in your wallet and get gen-u-wine parts from a for-real Toyota parts retailer or wholesaler?
HOW MUCH of a difference are you looking at?

Cars are like US Presidents.
Once they get a certain age things are going to go wrong no matter WHERE you get the replacement parts.
Your're driving a car that's over 100 years old in car years......in winter where "winter" means....REALLY.....Freekin' WINTER! in an ultra high crime area (don't mean to impugn your town(s) but with a "reported" vcrime rate of 50 per one thousand residents, your area is BAD....REALLY BAD - at least compared to all communities of all sizes - from the smallest towns to the very largest cities in the US....at least according to the Googles.)
.....HOW the heck much worse can it be using knock-off parts to maintain your 330,000 mile car?
Heck!
Buy re-tread tires too!

If I knew you were going to be driving it for another 100K, I'd tell you to buy lottery tickets!
LOTS of Lottery tickets, because you're the luckiest sonofagun I've ever heard of!!!

OK.
If you're still with me, I've poked a little fun at you and I almost apologize for that but here's the thing....(as my soon-to-be-former President would say...)
Amazon is NOT AT ALL the place to buy for-real Toyota parts!!!!!
They ARE the place to buy knock-offs that are just convincing enough to fool office workers who may or may not drive Toyotas but have never EVER worked on them!!!
Amazon WILL replace your parts and/or refund your money if they turn out to be bad.
If you buy them THIS TIME OF YEAR they'll even give you until 31 January to figure all that out!!!
BUT(!!)
You get to FIND OUT that the parts were crap....the hard way.
-right???

IN JANUARY.
IN Minnesota.

Me?
I'd buy the parts from a for-real, physical, brick and mortar Toyota dealer if I were you.

Good Luck!

 

Usually indicates head gasket failure, with Gen 3’s. Mostly to eliminate other possibility, swap plugs/coils around and see if misfire moves accordingly. My hunch: it won't.

 

Couldn't have said it better myself. 'Misfire' is what those codes mean, and they do not indicate any specific cause of the misfiring.

Even if this were the gen 3 forum and somebody suspected a certain thing that gen 3 misfires can be caused by, that might merit saying "might be worth checking if your misfires are being caused by X", but it wouldn't change what the codes mean.

 

Best course of action is to swap spark plug & ignition coil with #3 or #4 cylinder. restart the car and see if issue moves. If issue moves, swap ignition coils only, check again if issue moves. this test is to see if you have a spark plug, ignition coil, or combustion chamber issue. movement or no movement of issue is isolating the failure point.

hope this helps.... And better than the parts cannon approach...

 

It sounds like codes are hidden when a cat code, these engines are oil burners in their old age, hg do happeniioq