so yesterday on my way back home i noticed my check engine light go on and off but i was like thats since i bought it (02 sensor) but this tme it would go off and on,and then my car after a while just felt....sluggish so i checked it and it turns out i have misfires on my cylinder #3 and 4 but i just recently changed my spark plugs and spark plug wires. What could it be?

 

i had the same problem before .. turned out it was just bad gas .. i checked the plugs, wires and cap and rotor .. make sure u clean the inside of the cap if theres any metal filings inside .. never happened agen once the bad gas got used up .. the last time u fueled up did u see if there was the re-fueling truck putting gas in the station?

 

i agree,could be bad gas,mixed up with some water maybe =\

 

Yea there wasn't a truck just filled it up yesterday before work and I'll see if there is any metal stuck to the sparks but idk tried turning it on today and just wouldn't turn over I think maybe it's time for a swap :/

 

check all grounds too .. jes to be sure .. if theyre clean then i dont know .. check all ingredients for combustion: fuel, spark, compression and air .. maybe the engine compression is leaking out somewhere .. bad head gasket?

 

Possibly I check all sparks everythings fine no chips and no metal flakes so I guess time to check the gasket

 

perform a dry and/or wet (if numbers are low on the dry test) compression test the cylinders .. refer to your factory service manual or repair manual for specifications .. if numbers are low on the dry test then perform the 'wet' test (the wet test is for the piston rings only) .. inject a little bit of oil into each cylinder that is being tested .. this will make the rings help seal against the cylinder walls .. if the numbers go up dramatically then that is your problem ..

if u want u can perform a leak down test also jes for ease of mind .. leak downs pin point where you have leaks at ..

if it leaks into the head then ull hear escaping air leak out of the head and into the valve cover .. if it is a bad head gasket u can hear it escape out the cylinder that is next to it .. same thing for the exhaust manifold (could be the exhaust valves not seating right or is sticking open) .. and also if u see bubbles come out of the radiator fill port then u most likely have a blown head gasket or worse a cracked cylinder, but the latter will not likely happen under normal usage ..

anyone else can help chime in, im pretty sure i have missed a step or two .. jes got off work and im tired but i really wanna help u out with this problem, any questions that u have you can PM me about it and ill be glad to help