*Smog help!*

[JeepFreak]

A crack in the manifold is extremely common at the 'Y' joint where the two sides of the block come together to go down the exhaust. I have that same issue. You have a 95 so I'm gonna take a guess that you do not have more than one O2 sensor. I think before 96 all Jeeps had only upstream O2's. After 96, they had both upstream and downstream. So because the hole is before the sensor, yes it will cause false readings. Don't have the money to replace it? Go down to any auto store and buy VersaChem Exhaust System Joint and Crack Sealer. At AutoZone I think it was like 4-6. All it is is a putty that can withstand well more heat than your car will even get to (like temperatures that would melt your car) and you just paste it all over your crack in the manifold. Really simple. I had to do it to mine and I'll tell you what, the difference was IMMEDIATE. I mean I went from averaging 14MPG overall to averaging 16-17MPG overall. All you really need is a putty knife or something you can put it on then spread it and you are golden. Just let it dry overnight then drive it in the morning to cure it.

As for the plugs, I have heard that platinum plugs get pretty fudged up with buildup in our Jeeps although I am unclear as to why. I usually just stick with the gold ones from Bosch. If I had to take a guess, I would say it's because gold conducts electricity better than platinum.

Now the PCV/CCV does NOT have a specific replacement hose. You have to jury-rig it pretty much. Buy an equivalent sized hose, an equivalent sized grommet (mine is actually for a GM from Autozone LOL) and hook those bad boys up. It'll most likely crumble when you try to remove it but don't worry, it won't go down into your engine and kill your Jeep. Just make sure you have some sort of pliers or skinny grabbing device to remove ALL pieces that fell into it (it's only like an inch to an inch and a half to the bottom of the block since it only sucks in air).

[rm2406]

you are correct.. i only have 1 oxygen sensor, and its right after the crack in exhaust more than likely reading false. i have some stuff for the crack seal called "THERMO STEEL".
ive used it on past jeep with good results... dang jeeps and there cracked pipes!
as far as the plugs. i will be installing champion plugs again just thought id try out platinum..(no obvious results from that).
i also found high temp silicone hoses to replace old ones..
thanks for the help! very much appreciated!

[JeepFreak]

No problem. If you fix the leak and the Sensor and the plugs, you should test for the misfire. If it's misfiring a simple trick is to take a money bill (any denom) and hold one end up to the tailpipe. If it flaps around wildly, no misfire. If it SUCKS IN the bill like a lot and towards the pipe, then you have a misfire. Test it after the repairs and find out. If it's completely done misfiring, it probably solved your problem and you should have it retested. Even if you fail it gives you valuable insight. If the numbers changed at all and I mean by like more than 5 ppm, you know you're getting on the right track and something you did affected it.