1997 Hyundai Elantra Loss of power, gas mileage, surge, Mis

Hey Matt, oh no! You did a good job giving me symptoms. The bad news is, when the check engine light comes on and flashes, it also means that conditions are present to damage the catalytic convertor. What is going to help us now, is to get the codes retrieved so we can make a plan of attack.

You could go by just about any parts store and they'll retrieve the codes for you usually for free. Write down the codes numbers, don't worry about the descriptions. We'll go from there.

just had it plugged in and it read cyl one misfire. I failed to mention earlier that I also replaced all my plugs

Cylinder one missfire and no other codes present? It does have NGK or Denso spark plugs in it, yes? Do you have a volt meter so we can test the resistance on the number one ignition cable? If that checks out okay then I would start by pulling off the valve cover and check the valve train parts on number one especially.

Can you do that?

Not exactly sure what you are referring to but I have a friend that might know and I can use a volt meter. One thing to mention. At idle we pulled each spark plug wire one at a time. In each case we could hear the change when the wire was removed. So it seems as tho each plug is sparking. Not sure on the plug brand...just looked it up in the book and bought the recommended plugs

If you're sure the secondary ignition is up to par, then it's time to pull the valve cover and get a look.

Ok. How hard of a job is that? And what am I looking for?

Childs play I would call it. It's the cover on top of the cylinder head. If it's a cork gasket, get a replacement gasket. Once you pull the cover, you'll see all the rocker arms and springs. We want to check the rocker arms for looseness, and the spings for breaks or fatigue. Would your tech buddy be able to help out a little?

Ok we'll try that. Just one more thing. I'm still convinced that it isn't a faulty injector. If I swap two injectors and then it reads another cylinder misfire...can I then assume its a bad injector? Also, really dumb question but is my #1 cylinder the first on the left as you are looking at the engine? Thanks for you help

you are correct about the injector. Yes, number one is on the far left, the farthest cylinder from the coil pack. Did you give feedback? If not do so! :)

Keep me posted

I assume that the coil pack has been ruled out?

I have not considered the coil pack. Is there a way to test it to see if its weak or bad?

Remove one spark plug wire from its plug, then remove the spark plug using a spark plug socket. Next put the spark plug back into the spark plug wire. Be careful not to let anything drop into the empty spark plug hole. Holding the plug wire with insulated pliers, find a spot on the engine that is a good and easily accessible grounding point. Pretty much any exposed metal, including the engine itself, will do.

Holding the spark plug wire with your pliers, touch the threaded portion of the spark plug to the grounding point. Have somebody crank the engine with the key, and look for a bright blue spark to jump across the spark plug gap. If you see a nice, bright spark (clearly visible in daylight) your coil is doing its job.

Checked the spark. Seemed to be a little weak..looked white not blue. The plug looked pretty black.checked the other plugs and they were clean and dry. I did start this process with new plugs.

Get a coil pack.

I am having the same type of problem. Just curious if you bought a coil pack and whether or not it worked?