I have a tricky one for you, power issue/no start

2009 Toyota Corolla S -1.8 DOHC American Built

Okay so let me start off by saying my car was struck on December 24th 2022 by someone driving like an idiot, so the car was sitting for around 6 months before I got around to getting it all fixed. Entirely new front end, new lower control arms, inner/outer tie rods, new wheel hub and bearings, new everything basically. And what I did to one side, I did to the other. Reason I’m mentioning this is because I never had an issue with my car before the accident.

Now when I would go to start the car, it would take forever to fire up, so over the past 2 months I’ve put a lot of money into the engine by replacing the following.
-new ignition coils (all 4)
-new spark plugs (iridium pre-gapped)
-new injectors (as close to OEM as possible they are Denso)
-new O2 sensors (up and downstream)
-new crankshaft sensor
-new ambient temperature sensor
-new camshaft sensor
-new VVT solenoids (both of them)
-brand new fuel pump and filter
-new Mass Air Flow sensor

There’s probably some other things I’m missing but that’s the basic sum of it all. Needless to say I put around $2-3k into the car to try and fix the problem. Now when I try to start the car it cranks and cranks and cranks and takes forever to turn over. Now once it does turn over and start it seems to run a little rough, the idle just isn’t there at 1k RPM but after a while it seems to run Okay. When I take it for a drive I am having severe power issues, it’s sluggish to say the least and at high RPMs it’s almost like it’s not getting the fuel it needs to get up and go. It sputters when I put the pedal to the floor. Also when I am slowed down at a traffic light or something it bogs down so much that it’ll stall if I let it, so I have to put it in neutral to stop that from happening. I will also from time to time get a P0300, P0301, and a P0304 code which are all misfire codes, but that doesn’t make sense because normally that’s an ignition coil or plug problem but I have brand new everything. I have been scratching my head about this problem for weeks now and I can’t seem to figure out what the hell is going on! I even took it to my mechanic friend so he can run a diagnostic on it and he couldn’t figure it out. There’s no vacuum leaks, the compression is good, and the fuel pressure seems to be good. I was just curious if anyone had some of the same issues and if so, what did you do to fix this problem? I should also mention I did take the throttle body off and cleaned it up real good but I did not replace it. I am seriously at a loss with this car and it’s my fun little toy and would love to have it back on the road. Please please please, help me!

Was this incident not covered by insurance?

Yeah it was but that’s beside the point. I need to know what’s going on with the car, it’s driving me nuts

It’s really not beside the point. When the car was delivered to you not running in the same condition as before the crash, it should have immediately gone back to the mechanic or body shop to have that corrected at the insurance company’s expense. Unfortunately, given that apparently quite a bit of time has elapsed here, that’s probably not possible at this point.


After all that typing, not once do you mention the year of your Corolla.


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Yeah I apologize it’s a 2009 Toyota Corolla S with the 1.8

First off I never took it to a mechanic, I fixed the car myself, from top to bottom. So again the insurance is completely beside the point, I came on here for mechanical advice not financial advice.

You didn’t mention the battery.
That long sittling time could have damaged it.

I am thinking the battery probably went dead during the down time…

Did you do a throttle relearn???

Have you looked at live data yet??

Remove the O2 sensor before the catalytic converter to see if it starts and runs better.


I don’t know what you mean by ambient temp sensor but an engine temp sensor can cause delayed starting. There is also an air sensor. Cat, computer, etc could have been damaged. Be interesting to know the fuel trim readings when it is sluggish. Is the computer trying to lean the system or add more fuel. Etc, tester might have nailed it with a cat destroyed and+clogged from the impact.

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Some of those items you replaced are very unlikely related to the symptom. The O2 sensors for example are ignored by the computer until they reach full operating temperature, so not used on cold starts at all. One problem you should consider going forward is that one or more of the replaced parts were faulty right out of the box, and the original part was good. Hopefully you kept the removed parts and can use them for swap-tests.

My guess, something with the front portion of the exhaust system, exhaust manifold cracked, exhaust manifold gasket dislodged, flexible exhaust tube leaking or obstructed, front O2 sensor or its wiring. Suggest to approach the problem scientifically; i.e. change one thing at a time and test the result thoroughly before proceeding to the next potential culprit.

You’d probably save yourself a lot of time & grief by giving a pro-shop having the Toyota scan tool the opportunity to offer up a diagnosis based on their scan tool findings and diagnostic experience. You can still do the repairs yourself, based on their recommendations.

No experience w/you car, but I own a 1.6L Corolla. It’s exhaust manifold is located at the front of the engine compartment. Since your car crash damage was at the front, suggest to start by guessing what part(s) of the engine were most likely damaged. Did you take some post-crash photos of the engine compartment? You are welcome to post a few here if you like. I’m thinking the problem is something engine related in the front of the engine compartment.

  • Radiator
  • Exhaust manifold
  • Pre-cat O2 sensor & wiring
  • Flexible tube at the front of the exhaust system
  • Any sensors located in that area. In my car’s case that would be the engine coolant temp sensor (used by computer).
  • Battery and battery connections
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My own Corolla has an IAT sensor … Intake Ambient Temperature sensor. The temperature of the intake air in other words. That sort of sensor is usually just a thermistor, no moving parts, so unless there is visible damage, not a common failure item.

Ok. That might be the sensor in the air intake, I dunno. The engine temp sensor is what measure the actual temperature of the engine to tell the computer where to set the fuel ratio. Separate from the sender for the gauge or idiot light. How do I know? Cold Sunday morning on the side of the road. School of hard knocks, no mechanic training but I read a lot.

On my Corolla that’s called the ECT ( Engine Coolant Temperature) sensor. Screws into the coolant jacket, thermistor.

Inconstant nomenclature is a common problem w/car repair & diagnostics. For example a car’s engine computer might be called the ECM (engine control module), PCM (powertrain control module), ECU (engine control unit), DME (digital motor electronics)

Then of course there’s the problem that most modern cars have, a big fat rolling bevy of computers. BMW Module list, 240 of them.

Hey buddy, got one of them e39 modules in stock? I think mine is bad. Mind boggling.

You are good at replacing things, but not diagnosing things. Now if you go to a good shop to get a diagnosis they will likely have to recheck all your work , then follow a diagnostic tree. Diagnose first then replace. You spent a lot of money replacing parts that did not fix your problem without knowing if they were bad.


I appreciate all of that info, I definitely have been replacing one part at a time, and each time it seems like it’s getting better, I’ll drive it and it’ll be the same issue. I didn’t even think about cracked manifold, but I doubt it. I will have to check to be sure. The accident happen on the passenger side wheel well mainly, I replaced the exhaust manifold o2 sensor, not the cat o2 - so I will check that as well.

No I didn’t do a throttle relearn, and I took it to a mechanic who ran a diagnostic and he couldn’t find anything substantial either, my next step is to actually take it to Toyota

Well obviously I didn’t replace things for no reason, I was replacing things because A- figured they couldn’t hurt, only help, and B- based on the issues I’ve been having it made sense to replace them at the time. Again I didn’t replace them for no reason, If you look at every single part I replaced and the problem I’ve been having with the car, it all makes sense on why they were replaced.