Code P0172, no power when accelerating from a complete stop

ANDREW MEAKES

MEMBER
2008 TOYOTA CAMRY
2.4L
4 CYL
2WD
AUTOMATIC
130,000 MILES

When I put my foot on the accelerator from a complete stop there is 2 second lag before the car accelerates, It's showing a P0172 code. Have changed fuel injectors, fuel filter and pump, coils and plugs. Once the car is accelerating it's perfect and idles at 750 RPMs. It had blocked fuel injectors but that issues is resolved.

5 Replies

KASEKENNY

MECHANIC
18,907 POSTS

More than likely you have an issue with the MAF sensor but we need to run through this testing to find out what the actual issue is.

The P0172 is actually telling you that the system is rich so more then likely the MAF is reading low voltage which is telling the PCM that there is more air coming in then there actually is so it is dumping more fuel to compensate for the additional air.

It dumps too much fuel which throws off the air fuel mixture and you get a lack of power or a lag.

Here is a guide that will help with this but with a lean mixture. The idea is the same but it is rich instead.

https://www.2carpros.com/articles/repair-lean-mixture-codes-p0171-or-p0174-on-some-manufacturers

Below you will find the testing that we need to run through to figure out what the issue is.

Please let us know if you have other questions. Thanks

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Tuesday, June 29th, 2021 AT 6:08 PM

ANDREW MEAKES

MEMBER
3 POSTS

Just a follow up I cleaned the MAF sensor and the reading shows 2.6 (2.4 Ltr vehicle) and goes up proportionally on rpm. O2S11 seems normal 0.00mA at 2,000 RPMs. But when I start the vehicle from a cold start the choke kicks in but then seems to stop and the engine RPMs fall to 400 and nearly stalls or does stall then kicks back in again. The hesitation from acceleration from a complete stop to the time the car returns to normal is 2 seconds.

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Friday, July 2nd, 2021 AT 6:01 PM

KASEKENNY

MECHANIC
18,907 POSTS

I am not sure I understand what you mean by the "choke" kicks in. This is a throttle body vehicle so it doesn't have a choke.

Can you let me know what you are referring to and we can go from there? Thanks

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Saturday, July 3rd, 2021 AT 7:46 PM

ANDREW MEAKES

MEMBER
3 POSTS

Sorry choke is wrong word but I'm referring too when I start the car from cold start the car goes works up to 2,000 RPMs then quickly drops down to 400 and stalls. I then start it again (immediately) and it goes up to 2,000, then 1,500, then 1,000 and works its way to 700 as the engine heats up. When driving from a complete stop when I put my foot down it does nothing for 1.5 seconds then kicks in straight to 2,000 RPMs. Thanks for your help.

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Sunday, July 4th, 2021 AT 2:37 PM

KASEKENNY

MECHANIC
18,907 POSTS

Do you still have the same code?

This sounds like a possible vacuum leak so we need to check for that and see what comes back.

Here is a guide that will help to this test:

https://www.2carpros.com/articles/how-to-use-an-engine-vacuum-gauge

Also, if you have a vacuum gauge let's hook that to the engine on a vacuum line and see what the gauge does when this is acting up.

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