alright i will be pick up an inline 6 from a 99 tomorrow to be swapped into my 01 to replace the one with the cracked head. I've searched a lot and found a ton of good information but now i need some specifics like what extra parts i will need aside from the obvious. everything exterior of the motor is good on the 01 engine so i have plenty of parts to successfully convert it. my question now is what do i specifically need to do to make this thing work? and what can i do with my exhaust. I will be ordering new headers for the 99 but i have the 2 pre-cats that went along with some of the 00's and 01's, and the 99 only has the one down pipe, this also bring the question of will i need to swap in an ECU from a 99 because the missing pre-cats would cause the 01 ECU to believe there was something wrong?

 

Also I know you have to make a bracket to mount the coil packs if swapping to a 98 but will I need to make a bracket for the 99?

 

Yes, you can make a bracket if you need it. Everything else should bolt right up. It's almost a no brainer. Use the exhaust and computer from the body of the Jeep the motor is going into.

 

ok so im putting a 99 into an 01 so i use the 01 computer but what about the exhaust? all the 99 headers I've seen have 1 o2 sensor on the one down-pipe, but my 01 has 2 pre-cats so the headers have 2 down-pipes and 2 o2 sensors.

 

I have an 01 so i know what your talking about with pre cats. I'm not sure if its possible with the other motor but just bolt the 01 exaust and intake manifold it? Another option that sounds kind of crazy would be drill and tap another hole before and after the cat so that there is 2 upstream and 2 down stream for the 1 cat. It wont run right without all 4 o2 sensors on the 01 computer

 

Another crazy thing i just remembered is to have the ecu reflashed with the saudi arabia emmisions program as they have no emssions laws so its then possible to not run 02 sensors. But thats very illegal in the US eapecially if your in a state that does emmisions testing

 

Unfortunately the 01 and 99 headers don't match up because the holes are 1/2" off and it restricts airflow but if I were to swap a 99 ECU in then it should be fine running the one upstream o2 sensor right?

 

Im almost thinking you would have to other wise youll be throwing fault codes for ignition system since the coil packs wont be hooked up. It might not even start but I'm not 100% sure about how sophisticated the system is

 

i would test fit that exhaust before you start thinking it wont fit. I'm certain it will bolt right up. I'm standing right next to my brother's Jeep that we did it in.

 

heres what I am trying to say exhaust wise.
these are the 01 headers in my jeep now


these are 99 headers



so there is a difference of 1 o2 sensor and and the 2 pre-cats on the 01 so i dont know how they will line up properly

the problem is that everywhere i have looked says that i wont be able to use my 2001 headers on the 99 block because they are off 1/2 an inch

 

The '99 came with the 0630 head and there are many threads where people with the nortorious cracked 0331 head have replace it with the 0630 head without problems. That is what we did with my brother's jeep. There were no issues. It would make no sense what so ever to change over the complete engine electrical system and computer just to use a different exhaust manifold. Don't try to over-complicate it.

 

Doing a 99 into a 01, aside from the exhaust header noted before. What is the best way to swap out the distributor for the cam shaft synchronizer? How do I make sure when I pull out the Distributor from the new motor that I place the CSS in correctly?

 

It's pretty simple. There is a hole for an alignment pin in the cam sensor drive that holds the rotor in place after removing the sensor. Set #1 cylinder on TDC compression and install the drive so the sensor is pointing straight rearward parallel with the block. You may have to turn the oil pump shaft it get it to line up with the drive. A screwdriver works for that. You should use a new 0-ring seal to prevent oil leaks.

The cam sensor controls injector timing and duration and will need to be set to zero with a scan tool after. The tool will show a + or - reading with the engine running and will compensate for around 3*, but should be 0* for best fuel management.