What would cause the check engine light to come on intermittently and constantly flash when it's on? We've changed the coils because it pulled a po351 engine code. very lost. please help. Thanks

SOURCE: Flashing Check Engine Light 99 Camry

light flashes when comp. picks up a skip pull code and it will be po300 random miss p0301 p0302 p0303 p0304 all are for that # cyl that has the miss best bet change wires and plugs check for oil on wire to plug end in spark plug hole leaking valve cover gasket or spark plug tubes...

SOURCE: 2000 accent keep getting check en light on codes 300, 303

• Here are the most common causes of a ,misfire.
• Base engine mechanical faults (valve train faults, excessive carbon buildup, low compression)
• Air Intake system is restricted, or there is a restriction in the Exhaust system
• Fuel pressure problems (fuel pressure is either too low or too high)
• Faulty fuel injectors (leaking, restricted or dirty fuel injectors)
• Faults in the Ignition system components and wiring
• Faults in the Ignition system components and wiring
• Vehicle driven while low on fuel, or it was run completely out of fuel

SOURCE: 07 lexus rx 350 with check engine light code p0304

Hi, did you ever get an answer? I have the same issue. Thanks.

SOURCE: check engine light was constantly on, now periodic flashing 4x's

Its your pcv and the hose running from your pcv to the top it should have a hissing sound if so follow it and move the hose around make sure hose aint pinched somewhere not allowing air flow.

Jeffrey Turcotte

• 8991 Answers
• Posted on Jan 23, 2011

SOURCE: 2005 dodge dakota 3.7l check engine light on/ code

Run standard misfire tests--pull plug, attach to wire, ground plug threads to engine and crank to observe spark. If spark is absent or weak, try a different plug/wire to narrow down to spark problem.
If spark is good, run compression test on bank to check for bad valve/gasket.
If compression is good, suspect injector.

Please see my tip at http://www.fixya.com/cars/r6715318-causes_gasoline_engine_misfires . These are generic instructions. If you get stuck or need specific instructions for your car, please get back to me with model, year and engine info.