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Toyota Highlander code po303 and PO430

What is the cause of Toyota Highlander 2007 code PO303 and PO430

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Dan Burke

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The p303 is a misfire on cylinder 3. Most likely a bad ignition coil. The p430 is an evaporate system code. (The system that goes off when your gas cap is loose). On Toyotas, most likely replacing the charcoal canister.

Posted on Aug 15, 2017


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SOURCE: 3 codes po303,uo101,uo107

break down of the codes is

po303 - that would be a misfire on cylinder 3
uo101 - cant communicate with TCM
uo107 - lost communication with throttle actuator control module

Posted on May 28, 2009



  • 115 Answers

SOURCE: reads codes of po300,po302,po303,po305

Hi these are mis-fire codes ,
P0300 is a general mis-fire detected code the others relate to specific cylinders,
P0302 is cylinder 2 misfire
I would check your spark plugs first if Ok you need to make sure the coils are working ok for this you need an osciloscope to check output voltage if your not sure then take to a qualified mechanic with Cadilac experience it could be caused by an air leak,bad ECT sensor or even Mass air flow sensor ,codes only tell you the result not the cause

Posted on Jul 24, 2009


  • 407 Answers

SOURCE: i got coes po604, po303, po300, and po301 for my

miss fire codes need to check tune-up, proper spark at all cylinders

Posted on Oct 15, 2009


  • 1 Answer

SOURCE: po320 code and code po303 2004 lincoln navigator

Replaced a camshaft sensor still running rough & engine light still on, 2004 lincoln nav. 5.4 liter

Posted on Apr 28, 2010


Jonathan S

  • 749 Answers

SOURCE: PO303 PO353 codes on a 02 lincoln ls missfire?

P0353 - Ignition Coil 3 Control Circuit P0303 is a cylinder #3 misfire.Good chance the the cylinder 3 coil has failed.

Posted on Jun 06, 2010

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Went through a puddle and check engine light came on with code po303

this indicates a misfire on cylinder 3. it could have be plug, wire, coil. the water may have caused a short when these items got wet.

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code po303 refers to cylinder 3--misfire detected===causes --engine mechanical fault---wiring---ignition/ fuel system---injector---ECT/MAF sensor---ECM. check plug and HT lead to no 3 cylinder. Check that the injector to 3 cylinder is operational and not blocking or squirting. Have a compression test done to check for compression / gasket problems

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What does the code po303 mean

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PO303 PO353 codes on a 02 lincoln ls missfire?

P0353 - Ignition Coil 3 Control Circuit P0303 is a cylinder #3 misfire.Good chance the the cylinder 3 coil has failed.

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2 Answers

My check engine light came on the day after I had my car smog checked. My Tech noted error codes po136, po174, po303 and po305, It's a 2002 Highlander with only13,660 miles on it. Toyota had it for a...

the po303 and p0305 codes are indicating a cylinder 3 & 5 MISFIRE respectively. the other codes are for o2 sensor and fuel trim. the misfire codes should be fixed first and then worry about the others if they still exist. if the vehicle has direct ignition or coil on plug, this is a good place to start, the ignition coils for those cylinders. a scanner with a misfire monitor would really help to narrow done the problem and as always a tune-up never hurts if it hasn't been done for some time or plugs, air filter, etc, show signs of deterioration. the misfire codes if left untreated will release raw hydrocarbon emissions into the environment not to mention the damage it could cause to your catalytic converter due to overheating. also your gas mileage will suffer. hope this will help yoy

Jan 28, 2010 | 2002 Toyota Highlander

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