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1999 Toyota Camry Question: Fluctuating Idle with P0401 and P0402 codes



Quma, 2.2L 4 Cylinder, Indianapolis, IN, May 15, 2014, 21:36

I had 1999 Camry engine replaced recently. The idle needle pin fluctuate as the engine become hot. The codes are P0401 and P0402. I had it replaced EGR modulator, EGR valve and EGR solenoid. Did not fix. I clean throttle body with carbon cleaner and spray the hole to IAC inlet. Nothing changed.

What could be the reason and the solution to it.

In a youtube video bad DPFE sensor (EGR position sensor) causes P0401 to come up. However, someone in the forum says there is no EGR position sensor with this model. I need helps...

1 Answer
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  • Answer #1

    May 16, 2014, 10:23

    fluctuating idle most likely cause is bad idle control valve as for the codes need test egr switching valve if is a 4 cylinder engine is located under intake manifold and check vacume diagram to ensure hoses connected correctly

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  • Reply

    Quma, May 16, 2014, 18:08

    When I disconnect the hose that goes from modulator to EGR valve, the idle is normal. Could it still be the IAC problem?

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