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Rookie Wrencher with 2008 Corolla
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36 Posts
Discussion Starter #21
Do you have the freeze frame data from your misfire code?

Do you have battery voltage at pin 1 (pin closest to connector release) to ground on each fuel injector? Can you verify you have continuity between the injector pin 2 and ECU and no continuity between pin 2 and ground:
Thanks for the feedback hardtop.

I have 12V between pin1 and ground and no continuity between pin2 and ground, all 4 cylinders. I also have NO CONTINUITY between pin2 and ECM harness on all 4 cylinders.
 

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Rookie Wrencher with 2008 Corolla
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36 Posts
Discussion Starter #22
Your issue sounds fuel related. Basically if one injector is flowing too little or too much and affecting fuel trims, the computer will attempt to adjust injector volume for the remaining cylinders to compensate. If one is not running at all, it will increase the duty cycle to others resulting in a rich mixture. Conversely if one is leaking and running rich, it will remove fuel from the others causing a lean.

These issues will repeat over and over again as the computer attempts to fix the resulting rich and lean mixtures.

A flashing check engine light means your misfire counts and catalytic converter temperature have gone so high you risk damaging the cat.
Thanks for this! Starting to make sense.
 

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Super Moderator
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Thanks for the feedback hardtop.

I have 12V between pin1 and ground and no continuity between pin2 and ground, all 4 cylinders. I also have NO CONTINUITY between pin2 and ECM harness on all 4 cylinders.
Its possible your 2008 has different ECM terminals then the 2005 pictured, though it's unlikely. You should have continuity or the injectors wouldn't fire. Remember the injectors are checked to each individual ECU pin for that (e.g. Injector 1 Pin 2 to E3 Pin 1, Injector 2 Pin 2 to E3 Pin 2, Injector 3 Pin 2 to E3 Pin 3, and Injector 4 Pin 2 to E3 Pin 4). Injectors are from front to rear starting at the belt area and ending at the transmission. So Injector 1 is towards the belt and Injector 4 is towards the transmission.

If you need exact terminal specifics, check techinfo.toyota.com. You can get a 2 day subscription and have access to the entire Toyota TIS repair website. From there you can download all the required documents.

I don't have a 2008 ECM or general wiring diagram.
 

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I am sure your ECM is OK.
Dead ignition coils are very common on any car. They die pretty close to each other timewise. Pretty often I see cars with a few bad coils(bad coils kill O2 sensors and cat. converters.). Another common problems are dirty or bad MAF and dirty throttle. It is a good idea to check air filter. Do not use K&N air filters.
Recently I bought a Jaguar, it had 4 (out of 6) bad coils and dead O2 sensor, killed by bad coil.(car doesn't matter)
 

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Rookie Wrencher with 2008 Corolla
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36 Posts
Discussion Starter #25
Its possible your 2008 has different ECM terminals then the 2005 pictured, though it's unlikely.
Oops! I was looking at the diagram wrong. I had the wrong connector pulled. So I pulled my head out and redid the test and all 4 cylinders have continuity, between .1 and 0 ohms
 

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Oops! I was looking at the diagram wrong. I had the wrong connector pulled. So I pulled my head out and redid the test and all 4 cylinders have continuity, between .1 and 0 ohms
Can you measure resistance of the actual injectors?
 

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Senior TN Member
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7,508 Posts
Switch position of the injectors.
Put dark fouled ones in place of clean ones.
Put clean ones in place of dark fouled ones.
Run it for same amount of time as before.

This will allow us to distinguish if issue is injectors themselves or if it's harness issues of some sort.
 

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I think we can rule out wiring.

Typically the way to find these problems without parts or an oscilloscope is to swap around injectors and coils. If the misfires follow a particular coil or injector, you replace it.

Did this issue start suddenly or after some previous problem/event?
 

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Rookie Wrencher with 2008 Corolla
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36 Posts
Discussion Starter #31
Did this issue start suddenly or after some previous problem/event?
Came on sudden, no prior problem except I did note I was 1-1/2 quarts high on oil since my last service at the lube shop, 2000 miles ago. I had filled up with, gas a day or two earlier, from a sizable local chain and have had no problems with their gas.

Started with P0300, 301 and 304 and lots of smoke with a gas smell when cold. After warming up, the smoke stopped, it would run good and all cylinders were firing. Below about 2500 rpms I would feel a hesitation and a puff of smoke, I would need to baby the throttle from a stop to keep from dying. Also got codes P2195 and P0420 during some diagnostics, resets and test drives.

It has gotten worse since I did the following:
Replaced intake manifold gasket, new spark plugs with .043 gap, cleaned throttle, new PCV, cleaned MAF, new air filter and replaced #4 injector (new Denso 297-0017 in #4). Checked spark and compression, all cylinders good.

Now I can't run for more than 30 seconds and get flashing CEL. There is a lot more smoke now.
 

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Ok so I took some time to reread your freeze frame and the P2195 malfunction steps.

We need to rule out your A/F sensor and Bank 2 sensor.

Do the following and report back:

Check the A/F sensor voltage three times, when the engine is in each of the following conditions:
(1) While idling (check for at least 30 seconds)
(2) At an engine speed of approximately 2,500 rpm (without any sudden changes in engine speed)
(3) Raise the engine speed to 4,000 rpm and then quickly release the accelerator pedal so that the
throttle valve is fully closed.

If the A/F sensor is stuck at a voltage of 3.8 or more during all three, you have a shorted A/F sensor. This will cause all of your problems. If the voltage moves normally with RPM (around 3.1 - 3.3V) then the sensor is not the problem and we need to look elsewhere.

Here is the harness check for the A/F Sensor (you already got good readings on the heater):

 

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Rookie Wrencher with 2008 Corolla
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36 Posts
Discussion Starter #33
Check the A/F sensor voltage three times, when the engine is in each of the following conditions:
A few questions:

I'm voltage testing both front and rear sensors, is that correct?
What is best practice for testing, a wire piercing tool?
I'm concerned about reaching the RPMs listed and the time to do so. How long do I dare run the engine with CEL flashing?
Should I check harness and heater on bank 2 sensor?

Thanks Hardtop for all your help and time!
 

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A few questions:

I'm voltage testing both front and rear sensors, is that correct?
What is best practice for testing, a wire piercing tool?
I'm concerned about reaching the RPMs listed and the time to do so. How long do I dare run the engine with CEL flashing?
Should I check harness and heater on bank 2 sensor?

Thanks Hardtop for all your help and time!
1. No only the upstream wideband sensor (A/F) sensor. The other sensor is a narrow band O2 sensor and that will also be checked later.

2. You are checking with the harness unplugged so you can check right from the pins in front.

3. That I am not sure of. Rather than 30 seconds. Try 10 seconds and see what you get. You have the get into closed loop though.

4. Yes, but you need to rule out the A/F sensor as well. All of this assumes your timing is on, your injectors are plugged in, you didn't leave the brake booster hose or PCV hose disconnected during the intake gasket replacement, and there are no other obvious signs of damage.

I would be interested to see if the car runs better or at all without either:

A. The A/F sensor plugged in
B: The O2 sensor unplugged
 

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Oops! I was looking at the diagram wrong. I had the wrong connector pulled. So I pulled my head out and redid the test and all 4 cylinders have continuity, between .1 and 0 ohms
Yeah, the manual's diagram of the ECM connectors (you can see it in post 20 and 32) is upside down. This also threw me off when I was trying to diagnose a P0134. I kept following the diagram and finally realized it was upside down because I saw that the connector release tabs were on the top in the diagram, but they are actually on the bottom (floor side).
 

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Rookie Wrencher with 2008 Corolla
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36 Posts
Discussion Starter #36
Yeah, the manual's diagram of the ECM connectors (you can see it in post 20 and 32) is upside down. This also threw me off when I was trying to diagnose a P0134. I kept following the diagram and finally realized it was upside down because I saw that the connector release tabs were on the top in the diagram, but they are actually on the bottom (floor side).
Yeah, not only upside down but need to realize I'm looking at the back, wire side of the connector rather than the socket side I'm testing!
 

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Rookie Wrencher with 2008 Corolla
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36 Posts
Discussion Starter #37
1. No only the upstream wideband sensor (A/F) sensor. The other sensor is a narrow band O2 sensor and that will also be checked later.

2. You are checking with the harness unplugged so you can check right from the pins in front.

3. That I am not sure of. Rather than 30 seconds. Try 10 seconds and see what you get. You have the get into closed loop though.

4. Yes, but you need to rule out the A/F sensor as well. All of this assumes your timing is on, your injectors are plugged in, you didn't leave the brake booster hose or PCV hose disconnected during the intake gasket replacement, and there are no other obvious signs of damage.

I would be interested to see if the car runs better or at all without either:

A. The A/F sensor plugged in
B: The O2 sensor unplugged
The A/F harness checks out good, no opens, no shorts and 12V at the +B terminal.

With the A/F unplugged I could only get about 15 seconds of run time before the CEL started flashing. Not sure how fast the A/F generates it's voltage but I was only reading 2MV across the AF+ and AF- terminals after 15 seconds.

Plugged the A/F back in and got almost a minute of run time before CEL flashing. Checked codes and only got P0303 after final run, no P0300 or P0304 like last time. The freeze frame data changed so I included the new data if you need it.

Didn't try running with the O2 sensor unplugged. Need to pick up some jack stands before I get under the car.

Would it be a good time to swap around injectors and coil packs?
 

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Super Moderator
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It sounds as if you have 3 leaky injectors (1, 2, and 4) or 1 weak injector (injector 3).

Try this:

Swap the #3 injector to cylinder 1. Reset ECM, check for codes.

If code becomes P0301, you likely have an injector problem with injector 3 (which would then be injector 1), but you could also have leaky fuel injectors 1, 2, 4 (now 2, 3, 4).

If code remains P0303, swap coil in cylinder 3 to cylinder 1.

If code becomes P0301, you have a coil problem.

I would you have a problem with all of your injectors (common with age), but I would like to see results of an injector swap.
 

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Rookie Wrencher with 2008 Corolla
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36 Posts
Discussion Starter #39
It sounds as if you have 3 leaky injectors (1, 2, and 4) or 1 weak injector (injector 3).

Try this:

Swap the #3 injector to cylinder 1. Reset ECM, check for codes.

If code becomes P0301, you likely have an injector problem with injector 3 (which would then be injector 1), but you could also have leaky fuel injectors 1, 2, 4 (now 2, 3, 4).

If code remains P0303, swap coil in cylinder 3 to cylinder 1.

If code becomes P0301, you have a coil problem.

I would you have a problem with all of your injectors (common with age), but I would like to see results of an injector swap.
Swapped injector #3 with #1, reset codes, about 45 seconds before flashing CEL. 3 codes, P0300, 303, 304. No freeze data.

Swapped coil pacs #3 to #1 and #4 to #2, reset codes, about 45 seconds before flashing CEL. 3 codes, P0300, 303, 304. No freeze data.

Sounds like these tests eliminated coil and injector problems. I have checked, rechecked and checked again my work and not seeing any issues. I would like to check timing. I'm guessing I need to pull the valve cover, found Hardtop's write up for this, but I can't find any info on checking the timing. Can anyone point me in the right direction?
 

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Rookie Wrencher with 2008 Corolla
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Discussion Starter #40
Could the problems and symptoms I am having with my Corolla be caused by a restricted or faulty catalytic converter?
 
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