Codes P0300, P0301, P0302, P0303 and P0304 at a cold idle

MARTY NORTHOUSE

MEMBER
2002 TOYOTA CAMRY
2.4L
4 CYL
2WD
AUTOMATIC
80,000 MILES

When I started up the car in the morning (cold) 45 degrees. The check engine light came on. P0300, P0301, P0302, P0303, and P0304 showed up. I checked with a code reader. The car ran rough cold and after the car warms up it has no problem running, at an idle.
I reset the codes, then reprogrammed the computer to learn the idle. All codes were cleared. I shut off the car and started it several times warm. No check engine light or codes. The next morning when I started the car the idle was rough and I had to keep my foot on the accelerator or the car would shut off.
Then I would proceed to do the same thing with the same results so now I am stumped. Any help?

7 Replies

ASEMASTER6371

MECHANIC
52,797 POSTS

Good afternoon.

How old are the ignition system parts, such as plugs etc?

Beyond that, Toyota has real issues with carbon on the intake valves. When this happens, the engine runs terrible when cold and fine when hot. When the engine is cold the carbon absorbs the fuel and starves the cylinder for fuel. When the engine gets hot, the carbon gets hard and will not absorb the fuel and passes it off to the cylinder.

You should find a shop that can do a de carbon for you. Many do this with top engine cleaner and some use acorns to blast the carbon off the face of the intake valves.

The worse case scenario is the head will have to come off and the valves removed and cleaned.

Roy

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Tuesday, December 11th, 2018 AT 1:15 PM

MARTY NORTHOUSE

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4 POSTS

Thanks, Roy. I have ordered four brand new plugs. Besides that the ignition system is six years old. December 2012 I had a new engine installed because the car needed a head gasket. Do you think that I can buy a fuel treatment to clean the valves of the fuel injectors, or valves?

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Tuesday, December 11th, 2018 AT 1:23 PM

ASEMASTER6371

MECHANIC
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No, none of that stuff works. There is no cleaner you can add that will have any effect on this. Besides, fuel additive only try to clean injectors.

This is a cleaning into the intake manifold directly and then to the face of the intake valve in the head.

Roy

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Tuesday, December 11th, 2018 AT 1:25 PM

MARTY NORTHOUSE

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4 POSTS

Hello, Roy
I received the plugs, no change. But the car cold is idling at 400 rpm's and 600 when warmed up. Someone told me something about an automatic choke that is connected to the throttle body. That it can be adjusted or maybe a new one. Thanks

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Tuesday, December 25th, 2018 AT 5:47 AM

ASEMASTER6371

MECHANIC
52,797 POSTS

OK, no, that person has no clue how a fuel injection system works.

Choke used to be used on carb models and is never used on fuel injected models.

You are going to need to start where I told you in the beginning. It could be carbon build up on the valves or fuel delivery issue.

Roy