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

Engine misfire code probaly have a coil or plug wire going bad

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

i still have same code po303 i have change spark plugs and coil i add a ground wire i can resat end drive for 20+ milages no check enigine light
turn off start up runs for minute or so then coms back on check enigine light same po303 enigine runs very smoth no vibration what so ever I AM LOST

Is there an illuminated check engine light on the dash? That sounds like a failing TPS (throttle position sensor). Unless you have low fuel pressure! When (if ever) have you replaced the fuel pump and/or fuel filter? Are you running the correct type of fuel in the engine? If you have slow or sticky fuel injectors, a can of Seafoam might help!

I would start by replacing the spark plugs and wires

this code identifies that the computer in your vehicle has picked up that cylinder 3 is not fireing properly so i would say change the plug in cylinder 3 if not cured change the plug lead if thes dosent work then distributer cap or the electronic distributer check all these things in this order its just elimination really

I have 2002 Accord se I have engine light on, cod is po303 cly 3 misfire and po1399 ignition manuf- may misfire, I replaced new plugs, wires, distributor and cap, o2 sensor,head gasket, an Light still cam on. can any one help.

P0128 is coolant temp below threshold, and P0303 is a misfire at #3 cylinder-check your connection at the engine temperature control sensor and consider replacing the thermostat (is your temp gauge running unusually low?-might have a stuck open thermostat, it does happen)-this might be causing your engine computer to keep the engine in open loop, thinking it is not warmed up-if you have a bad plug wire at #3, or it is firing the injector rich, it might have tripped the P0303-no matter what, it does not sound real expensive, worst case you replace the thermostat, the ETC, plugs, cap, rotor and plug wires-less than $100 total, and it should run like new. While you are at it, clean the throttle body, it will help everything since it will run smoothly too.

PO303-cylinder #3 misfire
PO722-Output Speed Sensor No Signal

www.engine-light-help.com/generic-check-engine-light-codes.html

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