After reading so many post here, I've come to the conclusion I need to change my head gasket. (to start with) my #1&2 spark plugs are misfiring after the rig over heated. The check engine light came on yesterday so I did the turn key code finder ~
1 2 43 43 43 56. I just replaced the plugs about 3 mo. ago, and don't drive much. I pulled them and cleaned them. They weren't that bad at all. The white insulator was still really white. After doing so, the check engine light went off.
FYI when I first changed them after the rig getting hot, the light came on 3 days later, did the code check, and same thing, ONLY the # 1&2 plugs were black as can be, changed them and lasted till just yesterday, when the light came on. which tells me it's probably not a cracked head. This is why, I'm trying the gasket fix first. If it were a cracked head, I would think it would be just as black as before and not have lasted so long before the light came back on. My rig hasn't had a smooth idol since it got hot, and had the CC changed.
So, does anyone know why it is suggested to change the head bolts? I'm looking at close to $100.00 for just one side if I change the bolts to. I'd rather change the gasket on both sides, but if it's SO important I'll do them separately and buy both gasket and head bolts for the one side.
AND, does anyone have any info on how much it would cost to get all 5 door locks changed on a 96 Cherokee sport, and maybe recommend an honest place in bend Oregon? I appreciate all of you, you've helped immensely with all your post. thanks so much.

 

First we need to get a year and motor size so we can help better. Black plugs usually don't signify a head gasket leak. Usually the plugs are exceptionally clean from being flashed with steam. Coolant low with no wet spots? How's your oil look? Milky? I'd drain the oil and verify that first. At least pull the dip stick and look for "milkshake" on it.

 

It's a straight six.

There's one gasket not two.

Advance auto sells headbolts for like $30.

If you're putting a new headgasket on the jeep it's worth the $60 or so to send the head to a machine shop to get redecked and checked for leaks. Just my two cents though.

 

my jeep is a 96 Cherokee sport, 4.0 L-6. My coolant is just a tad below the fill line on the reservoir jug, and my oil is reddish clear. I have two small leaks under the car, but rarely have to add any fluids. if it's not the gasket, could it be the sensor that leads to the CC? Please excuse my technology, I'm a novice and work on my car by direction of jeep forum, you- tube and instruction from the auto parts store, but when they changed the CC they didn't change that sensor that looks to me like it has something to with the cat. could it be dirty after the cat went haywire causing rough idol? thanks so muchfluid,trying to figure this out. ive been trying for a few months now. complete tune-up., I've put in a new tps( helped alot) new plugs & wires, coil, rotor battery cat, drained and changes fluids, and then some.

 

Thank you, Thank you, Thank you.
After much thought, I had realized my rig had only one head. DUH! I was tempering wrong, and to dark to go out tho look. This ~my budget can handle, and will be sure tho get the head bolts as well. And the suggestion of getting the head redecked, sound super sensible! I'm thinking that means smoothing the edges so the gasket makes a nice snug seal. very good thinking. This, I will also be sure to do. If this doesn't fix my plug #1&2 misfire problem I will return for more suggestions. Thank you soooooo
much! happy, happy, happiness to all! ^_^