Misfires on Cylinder 2

[khptown]

A little over a week ago my 03 Kia Rio Cinco started acting up, running rough and missing really bad. The check engine light came on and I got the code checked, and is was an MAF sensor code, I cleared that to see if it would come back on again, it didn't, but a code for cylinder 2 misfire keeps on coming up. I brought it to a mechanic to have diagnostics done for $65, and all he said was that it was misfiring on Cylinder 2, and told me that it may be an injector and to use some injector cleaner to see if that helps. It hasn't helped yet. I've also changed the spark plugs and coil pack and those did not help the problem either. If anybody has any ideas on what this could be, please help.

[ronjohn]

Did you check the wires or replace them also? You could try unplugging your injector for #2 if it stay's the same maybe try cleaning the injector and check the #2 plug wire. Check the resistance of the injector coil use http://www.kiatechinfo.com/ or it or maybe the injector solenoid is stuck closed just something to look at also clean the Iac Valve it may help and is a good thing to do anyway. Good luck with it keep us posted . Reguard's Ronjohn

[Kevster]

Check compression (especially on that cylinder). Get some MAF sensor cleaner and clean the MAF (be gentle and use only approved solvent). Pull injector and look to see if port is all gunked up (I'll bet it is). Spray it good with carb cleaner, and replace. Swap injector with another cylinder and see if problem moves with the swap. Double check gap on plug 2. (no more than .030"). CHeck for possible intake leak.
Kiatechinfo has troubleshooting guides like ronjohn said.....use them. You could have a simple bad wire/bad plug/ wrong gap/faulty injector, or more serious, a burnt valve or cylinder/piston damage. Often the true problem hides behind several codes and is elusive until you get more codes or follow the logic and find the cause. Good luck!

[khptown]

Well, I had the mechanic put my car on the hoist today to look at the Cat converter because a couple months ago, I had a catalyist efficiency code. He found that it was broke at the flex neck/pipe, right before the exhaust. So I'm going to get that fixed for $150 and hope for the best. Any thoughts?

[ronjohn]

I hope that fixes your problem. But I had that flex pipe go bad also, if it is the one going from the first to the second cat break also it only got louder than normal but no codes. if your car still runs like crap get your cat's checked out. Do you have power? my 2nd cat went bad at 130k and don't forget about cleaning your IAC valve and look for vacuum leaks esp the hose frome the PCV to the intake and follow kevsters advice also. Good luck with it. did you clean the maf sensor? we are just trying to help.

[khptown]

Yes I did clean the MAF sensor but it didn't help. I have very little power. It seems to do better if I put accelerate evenly. It can barely make it up a hill. Its really jumpy or shall I say sputtery. Definately something that needs fixed ASAP.

[khptown]

Its the flex pipe before the first O2 sensor. If that makes any sense. And the car has 111,000.

[ronjohn]

Ok makes sense now. I take it your exhaust is different than mine, my first cat is one part that bolts onto the exhaust manifold. then i have a pipe in between the the 1st and 2nd cat that has a flexible area like a mesh. That is what i was refering to. I take it you only have 1 cat. good luck with it. Reguards ronjohn

[czechnuts]

I was having some of the same issue for awhile. Changed Multipule things except plug wires. That was night n day.

[khptown]

Czechnuts, what was night n day? Plug wires? I haven't done those yet, and only because they look good and were replaced 3 years ago.