ok....my car has 100k miles on it and it was running really bad ( everytime I tried to accelerate it would hesitate bad) so I changed the plugs, wires and fuel filter. after that, everything ran perfect. about 2 weeks later it started again so i changed the 3 coils and nothing. I'm burning gas like crazy too. im not sure if this matters, but my anti-freeze was low and started to over heat. I checked the oil but didnt find anything on the dipstick except oil. if I am driving doing 50 or so, i floor it and it doesnt go anywhere!

any help would be great!

John

 

Check engine light?

Which DTCs are being set?

 

yes, the check engine light is on andthe first time it went on it was blinking! I dont have acess to the diagnostic tester.

 

Hmm. A blinking Check engine light indicates a misfire. Autozone will perform an OBDII scan free of charge, and even give you a definition of the codes. Try doing that before you panic. So you have already replaced the fuel filter, spark plugs, spark plug wires, and all three coil packs, correct? Does it misfire ALL the time, or is it a random type hesitation misfire? As in, if you start it right now and let it idle in Park, would it misfire?

 

When the light blinks it is usually an indication of misfire. Get the car scanned & see what the complaint is. Could be bad wires, plugs, coils, ignition module. The scan will pin it down.

 

The car has a tiny misfire in park.... A little rough idle. I will go to autozone tomorrow morning and see what it is....
it misfires more when the car is warmer though

 

I have 2 codes.... p0420 and p0301

 

po420------catalyst system efficiency below threshold (bank 1)
po301------cylinder 1 misfire detected

 

Fix the misfire and the cat code should clear out also. Too much raw fuel in bank 1 and the cat can't handle it, most likely from the misfire. Since only one cylinder is mifiring, the ignition module and coils should be good. Check the HT wire for #1 and the connection at both the coil and plug ends. Also check the spark plug, which by now should be fouled and in need replacement.

 

It happens.... did you push down really hard on the wire when you installed it? Sometimes they dont seat all the way and wiggle off, causing the plug not to fire, or misfire. This will be the reason for the fouled plug too.