I have a slight issue with my 2000 hyundai accent gs, 1.5l automatic.

A few weeks ago, I put some "STP" style fuel injector cleaner into my gas tank. Either A) It cleaned everything really well and clogged my injectors, or B) it turned into gunk and possibly clogged something else up.

Ever since that day, my issue is that the car "stutters" very slightly. When idling, it'll "hiccup." When I'm doing normal driving, 55-60mph at 2k RPM, It'll almost feel like a transmission slip.

I've went and replaced my Fuel pump, filter, and now I've done half a can of seafoam through the brake line power booster (vaccuum) straight into the engine, and the other half into my oil for further cleaning. I also applied Seafoam Deep Creep into my throttle body, just for further maintenance.

Ever since then, everything has been running noticably better, and I've had a huge increase in gas mileage, but there's still a slight hiccup that occurs during idle and driving.

If there's any other info that is needed to figure out what could be going on, please let me know.

I change the oil /filter, plugs, wires, air filter on a regular basis.

I also had to change the MAF at one point in time, as it died and the car wouldn't start at all.

Please help! Next thing I'm thinking about doing is changing the plugs / wires one more time (it's been about 5 months since my last change) just to see if I bought a faulty plug.

The car was put on a computer and the only error code that came up was one about my check engine light being out.

 

STP = Junk. Never use it again

Seafoam = Snake Oil. Never use it again. It does nothing. Adding it through the Throttle Body and the brake booster hose does not send it through the fuel injectors anyway.

My guess is the STP messed up your injectors. I'd suggest going to a trained mechanic to have them do a correct fuel injection cleaning. One that attaches to the fuel rail and sends the cleaner directly to the injectors. Most in-tank cleaners are only good at keeping already clean injectors clean. They do not clean dirty injectors well. I suggest Techron fuel system cleaner as the only "in-tank" cleaner I would use.

 

Thank you for the feedback!
I'll keep that in mind, I added Techron to my fuel today.
I also changed my oil, oil filter, plugs, and wires today as a general maintenance, as well as running a half of can of Seafoam through my vaccuum line a second time, (I did it before I read this.) However, I did notice a big difference of pick up and go in my car, as well as it generally running very smoothly overall.

However, I did notice something that I didn't the first time I added seafoam through the vaccuum line, I do believe I have a hole in my headers (or in that general area,) because when I was adding it through, I watched some of the fluid spurt out the front of it, and onto my engine just underneath my plugs. I also watched the smokey exhaust that would normally come out the back, seep out the front. If I had a secondary person with me at the time, I would have took pictures of it to post on here and show.

How much will getting that hole fixed cost me? Would it be a general cause of a hiccup, or big loss of horsepower? (Yeah yeah, it's a 4 cylinder. )

 

I doubt you have a hole in the exhaust. It's probably just the SeaFoam that dripped on the outside burning off the manifold.

 

The brake line power booster is in the rear of the engine, I had a funnel attached to the line and was pouring it directly into the vaccuum as the car was going.

I just don't understand how it can drip / spill onto the front, and leak down into a small puddle if I'm in the back of the engine doing the pouring.

The car is 12 years old now, and was mis-treated by the previous owner. (The dumb b.... ran the car out of oil every time because she didn't want to get it changed, as well as never doing any general maintenance on the car whatsoever.)

 

MAF was to blame, went out again just a day after 1 yr warranty expired.

BTW, Seafoam is the best product you can use for your car. Don't know where you learned your information.

 

Seafoam is junk. Nobody should use it.